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<span>Formation</span> </div> </a> <ul id="toc-Formation-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Stability" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Stability"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Stability</span> </div> </a> <button aria-controls="toc-Stability-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Stability subsection</span> </button> <ul id="toc-Stability-sublist" class="vector-toc-list"> <li id="toc-Stabilization" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Stabilization"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1</span> <span>Stabilization</span> </div> </a> <ul id="toc-Stabilization-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Destabilization" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Destabilization"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.2</span> <span>Destabilization</span> </div> </a> <ul id="toc-Destabilization-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Mechanical_properties" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Mechanical_properties"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Mechanical properties</span> </div> </a> <button aria-controls="toc-Mechanical_properties-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Mechanical properties subsection</span> </button> <ul id="toc-Mechanical_properties-sublist" class="vector-toc-list"> <li id="toc-Liquid_foams" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Liquid_foams"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.1</span> <span>Liquid foams</span> </div> </a> <ul id="toc-Liquid_foams-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Solid_foams" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Solid_foams"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.2</span> <span>Solid foams</span> </div> </a> <ul id="toc-Solid_foams-sublist" class="vector-toc-list"> <li id="toc-Elastomeric_foam" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Elastomeric_foam"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.2.1</span> <span>Elastomeric foam</span> </div> </a> <ul id="toc-Elastomeric_foam-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Energy_of_deformation" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Energy_of_deformation"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.2.2</span> <span>Energy of deformation</span> </div> </a> <ul id="toc-Energy_of_deformation-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Directional_dependence" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Directional_dependence"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.2.3</span> <span>Directional dependence</span> </div> </a> <ul id="toc-Directional_dependence-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> </ul> </li> <li id="toc-Applications" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Applications"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Applications</span> </div> </a> <button aria-controls="toc-Applications-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Applications subsection</span> </button> <ul id="toc-Applications-sublist" class="vector-toc-list"> <li id="toc-Liquid_foams_2" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Liquid_foams_2"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.1</span> <span>Liquid foams</span> </div> </a> <ul id="toc-Liquid_foams_2-sublist" class="vector-toc-list"> <li id="toc-Depopulation" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Depopulation"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.1.1</span> <span>Depopulation</span> </div> </a> <ul id="toc-Depopulation-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Solid_foams_2" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Solid_foams_2"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.2</span> <span>Solid foams</span> </div> </a> <ul id="toc-Solid_foams_2-sublist" class="vector-toc-list"> <li id="toc-Syntactic_foam" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Syntactic_foam"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.2.1</span> <span>Syntactic foam</span> </div> </a> <ul id="toc-Syntactic_foam-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Integral_skin_foam" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Integral_skin_foam"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.2.2</span> <span>Integral skin foam</span> </div> </a> <ul id="toc-Integral_skin_foam-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> </ul> </li> <li id="toc-Gallery" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Gallery"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Gallery</span> </div> </a> <ul id="toc-Gallery-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Foam_scales_and_properties" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Foam_scales_and_properties"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>Foam scales and properties</span> </div> </a> <ul id="toc-Foam_scales_and_properties-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">9</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Further_reading" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Further_reading"> <div class="vector-toc-text"> <span class="vector-toc-numb">10</span> <span>Further reading</span> </div> </a> <ul id="toc-Further_reading-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">11</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" title="Table of Contents" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Foam</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 65 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-65" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">65 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D8%B1%D8%BA%D9%88%D8%A9" title="رغوة – Arabic" lang="ar" hreflang="ar" data-title="رغوة" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-ast mw-list-item"><a href="https://ast.wikipedia.org/wiki/Espluma" title="Espluma – Asturian" lang="ast" hreflang="ast" data-title="Espluma" data-language-autonym="Asturianu" data-language-local-name="Asturian" class="interlanguage-link-target"><span>Asturianu</span></a></li><li class="interlanguage-link interwiki-az mw-list-item"><a href="https://az.wikipedia.org/wiki/K%C3%B6p%C3%BCk" title="Köpük – Azerbaijani" lang="az" hreflang="az" data-title="Köpük" data-language-autonym="Azərbaycanca" data-language-local-name="Azerbaijani" class="interlanguage-link-target"><span>Azərbaycanca</span></a></li><li class="interlanguage-link interwiki-bn mw-list-item"><a href="https://bn.wikipedia.org/wiki/%E0%A6%AB%E0%A7%87%E0%A6%A8%E0%A6%BE" title="ফেনা – Bangla" lang="bn" hreflang="bn" data-title="ফেনা" data-language-autonym="বাংলা" data-language-local-name="Bangla" class="interlanguage-link-target"><span>বাংলা</span></a></li><li class="interlanguage-link interwiki-bg mw-list-item"><a href="https://bg.wikipedia.org/wiki/%D0%9F%D1%8F%D0%BD%D0%B0" title="Пяна – Bulgarian" lang="bg" hreflang="bg" data-title="Пяна" data-language-autonym="Български" data-language-local-name="Bulgarian" class="interlanguage-link-target"><span>Български</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Escuma" title="Escuma – Catalan" lang="ca" hreflang="ca" data-title="Escuma" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cv mw-list-item"><a href="https://cv.wikipedia.org/wiki/%D0%9A%C4%83%D0%BF%C4%83%D0%BA" title="Кăпăк – Chuvash" lang="cv" hreflang="cv" data-title="Кăпăк" data-language-autonym="Чӑвашла" data-language-local-name="Chuvash" class="interlanguage-link-target"><span>Чӑвашла</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/P%C4%9Bna" title="Pěna – Czech" lang="cs" hreflang="cs" data-title="Pěna" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-sn mw-list-item"><a href="https://sn.wikipedia.org/wiki/Furo" title="Furo – Shona" lang="sn" hreflang="sn" data-title="Furo" data-language-autonym="ChiShona" data-language-local-name="Shona" class="interlanguage-link-target"><span>ChiShona</span></a></li><li class="interlanguage-link interwiki-cy mw-list-item"><a href="https://cy.wikipedia.org/wiki/Ewyn" title="Ewyn – Welsh" lang="cy" hreflang="cy" data-title="Ewyn" data-language-autonym="Cymraeg" data-language-local-name="Welsh" class="interlanguage-link-target"><span>Cymraeg</span></a></li><li class="interlanguage-link interwiki-da mw-list-item"><a href="https://da.wikipedia.org/wiki/Skum" title="Skum – Danish" lang="da" hreflang="da" data-title="Skum" data-language-autonym="Dansk" data-language-local-name="Danish" class="interlanguage-link-target"><span>Dansk</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Schaum" title="Schaum – German" lang="de" hreflang="de" data-title="Schaum" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-et mw-list-item"><a href="https://et.wikipedia.org/wiki/Vaht" title="Vaht – Estonian" lang="et" hreflang="et" data-title="Vaht" data-language-autonym="Eesti" data-language-local-name="Estonian" class="interlanguage-link-target"><span>Eesti</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Espuma" title="Espuma – Spanish" lang="es" hreflang="es" data-title="Espuma" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-eo mw-list-item"><a href="https://eo.wikipedia.org/wiki/%C5%9Ca%C5%ADmo" title="Ŝaŭmo – Esperanto" lang="eo" hreflang="eo" data-title="Ŝaŭmo" data-language-autonym="Esperanto" data-language-local-name="Esperanto" class="interlanguage-link-target"><span>Esperanto</span></a></li><li class="interlanguage-link interwiki-eu mw-list-item"><a href="https://eu.wikipedia.org/wiki/Apar" title="Apar – Basque" lang="eu" hreflang="eu" data-title="Apar" data-language-autonym="Euskara" data-language-local-name="Basque" class="interlanguage-link-target"><span>Euskara</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%DA%A9%D9%81" title="کف – Persian" lang="fa" hreflang="fa" data-title="کف" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/Mousse_(mati%C3%A8re)" title="Mousse (matière) – French" lang="fr" hreflang="fr" data-title="Mousse (matière)" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-ga mw-list-item"><a href="https://ga.wikipedia.org/wiki/C%C3%BAr_(coipeadh)" title="Cúr (coipeadh) – Irish" lang="ga" hreflang="ga" data-title="Cúr (coipeadh)" data-language-autonym="Gaeilge" data-language-local-name="Irish" class="interlanguage-link-target"><span>Gaeilge</span></a></li><li class="interlanguage-link interwiki-gl mw-list-item"><a href="https://gl.wikipedia.org/wiki/Escuma" title="Escuma – Galician" lang="gl" hreflang="gl" data-title="Escuma" data-language-autonym="Galego" data-language-local-name="Galician" class="interlanguage-link-target"><span>Galego</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%EA%B1%B0%ED%92%88" title="거품 – Korean" lang="ko" hreflang="ko" data-title="거품" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-hy mw-list-item"><a href="https://hy.wikipedia.org/wiki/%D5%93%D6%80%D6%83%D5%B8%D6%82%D6%80" title="Փրփուր – Armenian" lang="hy" hreflang="hy" data-title="Փրփուր" data-language-autonym="Հայերեն" data-language-local-name="Armenian" class="interlanguage-link-target"><span>Հայերեն</span></a></li><li class="interlanguage-link interwiki-hi mw-list-item"><a href="https://hi.wikipedia.org/wiki/%E0%A4%9D%E0%A4%BE%E0%A4%97" title="झाग – Hindi" lang="hi" hreflang="hi" data-title="झाग" data-language-autonym="हिन्दी" data-language-local-name="Hindi" class="interlanguage-link-target"><span>हिन्दी</span></a></li><li class="interlanguage-link interwiki-hr mw-list-item"><a href="https://hr.wikipedia.org/wiki/Pjena" title="Pjena – Croatian" lang="hr" hreflang="hr" data-title="Pjena" data-language-autonym="Hrvatski" data-language-local-name="Croatian" class="interlanguage-link-target"><span>Hrvatski</span></a></li><li class="interlanguage-link interwiki-io mw-list-item"><a href="https://io.wikipedia.org/wiki/Spumo" title="Spumo – Ido" lang="io" hreflang="io" data-title="Spumo" data-language-autonym="Ido" data-language-local-name="Ido" class="interlanguage-link-target"><span>Ido</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Busa" title="Busa – Indonesian" lang="id" hreflang="id" data-title="Busa" data-language-autonym="Bahasa Indonesia" data-language-local-name="Indonesian" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Schiuma" title="Schiuma – Italian" lang="it" hreflang="it" data-title="Schiuma" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/%D7%A7%D7%A6%D7%A3" title="קצף – Hebrew" lang="he" hreflang="he" data-title="קצף" data-language-autonym="עברית" data-language-local-name="Hebrew" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-jv mw-list-item"><a href="https://jv.wikipedia.org/wiki/Unthuk" title="Unthuk – Javanese" lang="jv" hreflang="jv" data-title="Unthuk" data-language-autonym="Jawa" data-language-local-name="Javanese" class="interlanguage-link-target"><span>Jawa</span></a></li><li class="interlanguage-link interwiki-kn mw-list-item"><a href="https://kn.wikipedia.org/wiki/%E0%B2%A8%E0%B3%8A%E0%B2%B0%E0%B3%86" title="ನೊರೆ – Kannada" lang="kn" hreflang="kn" data-title="ನೊರೆ" data-language-autonym="ಕನ್ನಡ" data-language-local-name="Kannada" class="interlanguage-link-target"><span>ಕನ್ನಡ</span></a></li><li class="interlanguage-link interwiki-kk mw-list-item"><a href="https://kk.wikipedia.org/wiki/%D0%9A%D3%A9%D0%B1%D1%96%D0%BA" title="Көбік – Kazakh" lang="kk" hreflang="kk" data-title="Көбік" data-language-autonym="Қазақша" data-language-local-name="Kazakh" class="interlanguage-link-target"><span>Қазақша</span></a></li><li class="interlanguage-link interwiki-ht mw-list-item"><a href="https://ht.wikipedia.org/wiki/Kim" title="Kim – Haitian Creole" lang="ht" hreflang="ht" data-title="Kim" data-language-autonym="Kreyòl ayisyen" data-language-local-name="Haitian Creole" class="interlanguage-link-target"><span>Kreyòl ayisyen</span></a></li><li class="interlanguage-link interwiki-lv mw-list-item"><a href="https://lv.wikipedia.org/wiki/Putas" title="Putas – Latvian" lang="lv" hreflang="lv" data-title="Putas" data-language-autonym="Latviešu" data-language-local-name="Latvian" class="interlanguage-link-target"><span>Latviešu</span></a></li><li class="interlanguage-link interwiki-lmo mw-list-item"><a href="https://lmo.wikipedia.org/wiki/Scuma" title="Scuma – Lombard" lang="lmo" hreflang="lmo" data-title="Scuma" data-language-autonym="Lombard" data-language-local-name="Lombard" class="interlanguage-link-target"><span>Lombard</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/Hab" title="Hab – Hungarian" lang="hu" hreflang="hu" data-title="Hab" data-language-autonym="Magyar" data-language-local-name="Hungarian" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-ms mw-list-item"><a href="https://ms.wikipedia.org/wiki/Busa" title="Busa – Malay" lang="ms" hreflang="ms" data-title="Busa" data-language-autonym="Bahasa Melayu" data-language-local-name="Malay" class="interlanguage-link-target"><span>Bahasa Melayu</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Schuim_(structuur)" title="Schuim (structuur) – Dutch" lang="nl" hreflang="nl" data-title="Schuim (structuur)" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E6%B3%A1" title="泡 – Japanese" lang="ja" hreflang="ja" data-title="泡" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-ce mw-list-item"><a href="https://ce.wikipedia.org/wiki/%D0%A7%D0%BE%D0%BF%D0%B0" title="Чопа – Chechen" lang="ce" hreflang="ce" data-title="Чопа" data-language-autonym="Нохчийн" data-language-local-name="Chechen" class="interlanguage-link-target"><span>Нохчийн</span></a></li><li class="interlanguage-link interwiki-no mw-list-item"><a href="https://no.wikipedia.org/wiki/Skum" title="Skum – Norwegian Bokmål" lang="nb" hreflang="nb" data-title="Skum" data-language-autonym="Norsk bokmål" data-language-local-name="Norwegian Bokmål" class="interlanguage-link-target"><span>Norsk bokmål</span></a></li><li class="interlanguage-link interwiki-nn mw-list-item"><a href="https://nn.wikipedia.org/wiki/Skum" title="Skum – Norwegian Nynorsk" lang="nn" hreflang="nn" data-title="Skum" data-language-autonym="Norsk nynorsk" data-language-local-name="Norwegian Nynorsk" class="interlanguage-link-target"><span>Norsk nynorsk</span></a></li><li class="interlanguage-link interwiki-pa mw-list-item"><a href="https://pa.wikipedia.org/wiki/%E0%A8%9D%E0%A9%B1%E0%A8%97" title="ਝੱਗ – Punjabi" lang="pa" hreflang="pa" data-title="ਝੱਗ" data-language-autonym="ਪੰਜਾਬੀ" data-language-local-name="Punjabi" class="interlanguage-link-target"><span>ਪੰਜਾਬੀ</span></a></li><li class="interlanguage-link interwiki-pnb mw-list-item"><a href="https://pnb.wikipedia.org/wiki/%D8%AC%DA%BE%DA%AF" title="جھگ – Western Punjabi" lang="pnb" hreflang="pnb" data-title="جھگ" data-language-autonym="پنجابی" data-language-local-name="Western Punjabi" class="interlanguage-link-target"><span>پنجابی</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Piana_(chemia_fizyczna)" title="Piana (chemia fizyczna) – Polish" lang="pl" hreflang="pl" data-title="Piana (chemia fizyczna)" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/Espuma" title="Espuma – Portuguese" lang="pt" hreflang="pt" data-title="Espuma" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ro mw-list-item"><a href="https://ro.wikipedia.org/wiki/Spum%C4%83" title="Spumă – Romanian" lang="ro" hreflang="ro" data-title="Spumă" data-language-autonym="Română" data-language-local-name="Romanian" class="interlanguage-link-target"><span>Română</span></a></li><li class="interlanguage-link interwiki-qu mw-list-item"><a href="https://qu.wikipedia.org/wiki/Phusuqu" title="Phusuqu – Quechua" lang="qu" hreflang="qu" data-title="Phusuqu" data-language-autonym="Runa Simi" data-language-local-name="Quechua" class="interlanguage-link-target"><span>Runa Simi</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%9F%D0%B5%D0%BD%D0%B0" title="Пена – Russian" lang="ru" hreflang="ru" data-title="Пена" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-scn mw-list-item"><a href="https://scn.wikipedia.org/wiki/Scuma" title="Scuma – Sicilian" lang="scn" hreflang="scn" data-title="Scuma" data-language-autonym="Sicilianu" data-language-local-name="Sicilian" class="interlanguage-link-target"><span>Sicilianu</span></a></li><li class="interlanguage-link interwiki-simple mw-list-item"><a href="https://simple.wikipedia.org/wiki/Foam" title="Foam – Simple English" lang="en-simple" hreflang="en-simple" data-title="Foam" data-language-autonym="Simple English" data-language-local-name="Simple English" class="interlanguage-link-target"><span>Simple English</span></a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/Pena" title="Pena – Slovak" lang="sk" hreflang="sk" data-title="Pena" data-language-autonym="Slovenčina" data-language-local-name="Slovak" class="interlanguage-link-target"><span>Slovenčina</span></a></li><li class="interlanguage-link interwiki-sl mw-list-item"><a href="https://sl.wikipedia.org/wiki/Pena" title="Pena – Slovenian" lang="sl" hreflang="sl" data-title="Pena" data-language-autonym="Slovenščina" data-language-local-name="Slovenian" class="interlanguage-link-target"><span>Slovenščina</span></a></li><li class="interlanguage-link interwiki-sr mw-list-item"><a href="https://sr.wikipedia.org/wiki/Pena" title="Pena – Serbian" lang="sr" hreflang="sr" data-title="Pena" data-language-autonym="Српски / srpski" data-language-local-name="Serbian" class="interlanguage-link-target"><span>Српски / srpski</span></a></li><li class="interlanguage-link interwiki-su mw-list-item"><a href="https://su.wikipedia.org/wiki/Budah" title="Budah – Sundanese" lang="su" hreflang="su" data-title="Budah" data-language-autonym="Sunda" data-language-local-name="Sundanese" class="interlanguage-link-target"><span>Sunda</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/Vaahto" title="Vaahto – Finnish" lang="fi" hreflang="fi" data-title="Vaahto" data-language-autonym="Suomi" data-language-local-name="Finnish" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/Skum" title="Skum – Swedish" lang="sv" hreflang="sv" data-title="Skum" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-th mw-list-item"><a href="https://th.wikipedia.org/wiki/%E0%B9%82%E0%B8%9F%E0%B8%A1_(%E0%B8%84%E0%B8%AD%E0%B8%A5%E0%B8%A5%E0%B8%AD%E0%B8%A2%E0%B8%94%E0%B9%8C)" title="โฟม (คอลลอยด์) – Thai" lang="th" hreflang="th" data-title="โฟม (คอลลอยด์)" data-language-autonym="ไทย" data-language-local-name="Thai" class="interlanguage-link-target"><span>ไทย</span></a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/K%C3%B6p%C3%BCk" title="Köpük – Turkish" lang="tr" hreflang="tr" data-title="Köpük" data-language-autonym="Türkçe" data-language-local-name="Turkish" class="interlanguage-link-target"><span>Türkçe</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/%D0%9F%D1%96%D0%BD%D0%B0" title="Піна – Ukrainian" lang="uk" hreflang="uk" data-title="Піна" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/B%E1%BB%8Dt" title="Bọt – Vietnamese" lang="vi" hreflang="vi" data-title="Bọt" data-language-autonym="Tiếng Việt" data-language-local-name="Vietnamese" class="interlanguage-link-target"><span>Tiếng Việt</span></a></li><li class="interlanguage-link interwiki-wa mw-list-item"><a href="https://wa.wikipedia.org/wiki/Schome" title="Schome – Walloon" lang="wa" hreflang="wa" data-title="Schome" data-language-autonym="Walon" data-language-local-name="Walloon" class="interlanguage-link-target"><span>Walon</span></a></li><li class="interlanguage-link interwiki-wuu mw-list-item"><a href="https://wuu.wikipedia.org/wiki/%E6%B3%A1%E6%B2%AB" title="泡沫 – Wu" lang="wuu" hreflang="wuu" data-title="泡沫" data-language-autonym="吴语" data-language-local-name="Wu" class="interlanguage-link-target"><span>吴语</span></a></li><li class="interlanguage-link interwiki-yi mw-list-item"><a href="https://yi.wikipedia.org/wiki/%D7%A9%D7%95%D7%99%D7%9D" title="שוים – Yiddish" lang="yi" hreflang="yi" data-title="שוים" data-language-autonym="ייִדיש" data-language-local-name="Yiddish" class="interlanguage-link-target"><span>ייִדיש</span></a></li><li class="interlanguage-link interwiki-zh-yue mw-list-item"><a href="https://zh-yue.wikipedia.org/wiki/%E6%B3%A1%E6%B2%AB" title="泡沫 – Cantonese" lang="yue" hreflang="yue" data-title="泡沫" data-language-autonym="粵語" data-language-local-name="Cantonese" class="interlanguage-link-target"><span>粵語</span></a></li><li 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free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><p class="mw-empty-elt"> </p> <div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Form of matter</div> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">This article is about the substance formed from trapped gas bubbles. For other uses, see <a href="/wiki/Foam_(disambiguation)" class="mw-disambig" title="Foam (disambiguation)">Foam (disambiguation)</a>.</div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951" /><div role="note" class="hatnote navigation-not-searchable">"Foaming" and "Foamy" redirect here. For a method of mass killing farm animals, see <a href="/wiki/Foam_depopulation" title="Foam depopulation">Foam depopulation</a>. For other uses, see <a href="/wiki/Foamy_(disambiguation)" class="mw-disambig" title="Foamy (disambiguation)">Foamy (disambiguation)</a>.</div> <style data-mw-deduplicate="TemplateStyles:r1251242444">.mw-parser-output .ambox{border:1px solid #a2a9b1;border-left:10px solid #36c;background-color:#fbfbfb;box-sizing:border-box}.mw-parser-output .ambox+link+.ambox,.mw-parser-output .ambox+link+style+.ambox,.mw-parser-output .ambox+link+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+style+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+link+.ambox{margin-top:-1px}html body.mediawiki .mw-parser-output .ambox.mbox-small-left{margin:4px 1em 4px 0;overflow:hidden;width:238px;border-collapse:collapse;font-size:88%;line-height:1.25em}.mw-parser-output .ambox-speedy{border-left:10px solid #b32424;background-color:#fee7e6}.mw-parser-output .ambox-delete{border-left:10px solid #b32424}.mw-parser-output .ambox-content{border-left:10px 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.ambox{border:none;border-collapse:collapse;background-color:transparent;margin:0 0 0 1.6em!important;padding:0!important;width:auto;display:block}body.mediawiki .mw-parser-output .compact-ambox .ambox.mbox-small-left{font-size:100%;width:auto;margin:0}.mw-parser-output .compact-ambox .ambox .mbox-text{padding:0!important;margin:0!important}.mw-parser-output .compact-ambox .ambox .mbox-text-span{display:list-item;line-height:1.5em;list-style-type:disc}body.skin-minerva .mw-parser-output .multiple-issues-text>.mw-collapsible-toggle,.mw-parser-output .compact-ambox .ambox .mbox-image,.mw-parser-output .compact-ambox .ambox .mbox-imageright,.mw-parser-output .compact-ambox .ambox .mbox-empty-cell,.mw-parser-output .compact-ambox .hide-when-compact{display:none}</style><table class="box-Multiple_issues plainlinks metadata ambox ambox-content ambox-multiple_issues compact-ambox" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/40px-Ambox_important.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/60px-Ambox_important.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/80px-Ambox_important.svg.png 2x" data-file-width="40" data-file-height="40" /></span></span></div></td><td class="mbox-text"><div class="mbox-text-span"><div class="multiple-issues-text mw-collapsible"><b>This article has multiple issues.</b> Please help <b><a href="/wiki/Special:EditPage/Foam" title="Special:EditPage/Foam">improve it</a></b> or discuss these issues on the <b><a href="/wiki/Talk:Foam" title="Talk:Foam">talk page</a></b>. <small><i>(<a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove these messages</a>)</i></small> <div class="mw-collapsible-content"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1251242444" /><table class="box-More_citations_needed plainlinks metadata ambox ambox-content ambox-Refimprove" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><a href="/wiki/File:Question_book-new.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png" decoding="async" width="50" height="39" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/75px-Question_book-new.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/100px-Question_book-new.svg.png 2x" data-file-width="512" data-file-height="399" /></a></span></div></td><td class="mbox-text"><div class="mbox-text-span">This article <b>needs additional citations for <a href="/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">verification</a></b>.<span class="hide-when-compact"> Please help <a href="/wiki/Special:EditPage/Foam" title="Special:EditPage/Foam">improve this article</a> by <a href="/wiki/Help:Referencing_for_beginners" title="Help:Referencing for beginners">adding citations to reliable sources</a>. Unsourced material may be challenged and removed.<br /><small><span class="plainlinks"><i>Find sources:</i> <a rel="nofollow" class="external text" href="https://www.google.com/search?as_eq=wikipedia&q=%22Foam%22">"Foam"</a> – <a rel="nofollow" class="external text" href="https://www.google.com/search?tbm=nws&q=%22Foam%22+-wikipedia&tbs=ar:1">news</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?&q=%22Foam%22&tbs=bkt:s&tbm=bks">newspapers</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?tbs=bks:1&q=%22Foam%22+-wikipedia">books</a> <b>·</b> <a rel="nofollow" class="external text" href="https://scholar.google.com/scholar?q=%22Foam%22">scholar</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.jstor.org/action/doBasicSearch?Query=%22Foam%22&acc=on&wc=on">JSTOR</a></span></small></span> <span class="date-container"><i>(<span class="date">February 2012</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1251242444" /><table class="box-Original_research plainlinks metadata ambox ambox-content ambox-Original_research" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/40px-Ambox_important.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/60px-Ambox_important.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/80px-Ambox_important.svg.png 2x" data-file-width="40" data-file-height="40" /></span></span></div></td><td class="mbox-text"><div class="mbox-text-span">This article <b>possibly contains <a href="/wiki/Wikipedia:No_original_research" title="Wikipedia:No original research">original research</a></b>.<span class="hide-when-compact"> Please <a class="external text" href="https://en.wikipedia.org/w/index.php?title=Foam&action=edit">improve it</a> by <a href="/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">verifying</a> the claims made and adding <a href="/wiki/Wikipedia:Citing_sources#Inline_citations" title="Wikipedia:Citing sources">inline citations</a>. Statements consisting only of original research should be removed.</span> <span class="date-container"><i>(<span class="date">December 2020</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1251242444" /><table class="box-Lead_rewrite plainlinks metadata ambox ambox-style ambox-lead_rewrite" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/f/f2/Edit-clear.svg/40px-Edit-clear.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/f/f2/Edit-clear.svg/60px-Edit-clear.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/f/f2/Edit-clear.svg/80px-Edit-clear.svg.png 2x" data-file-width="48" data-file-height="48" /></span></span></div></td><td class="mbox-text"><div class="mbox-text-span">The article's <a href="/wiki/Wikipedia:Manual_of_Style/Lead_section" title="Wikipedia:Manual of Style/Lead section">lead section</a> <b>may need to be rewritten</b>. The reason given is: <b>lead fails to summarise, instead presenting novel content (dispersed media, quantum foam, and allusions to foam as polydisperse, colloidal, and as suds, beer head, bath sponges, etc., all <i>only</i> in lead).</b><span class="hide-when-compact"> Please help <a class="external text" href="https://en.wikipedia.org/w/index.php?title=Foam&action=edit">improve the lead</a> and read the <a href="/wiki/Wikipedia:Manual_of_Style/Lead_section" title="Wikipedia:Manual of Style/Lead section">lead layout guide</a>.</span> <span class="date-container"><i>(<span class="date">August 2024</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1251242444" /><table class="box-Essay-like plainlinks metadata ambox ambox-style ambox-essay-like" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/f/f2/Edit-clear.svg/40px-Edit-clear.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/f/f2/Edit-clear.svg/60px-Edit-clear.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/f/f2/Edit-clear.svg/80px-Edit-clear.svg.png 2x" data-file-width="48" data-file-height="48" /></span></span></div></td><td class="mbox-text"><div class="mbox-text-span">This article <b>is written like draft academic essay/treatment, from sources unstated,</b> that states a Wikipedia editor's personal feelings or presents an original argument about a topic.<span class="hide-when-compact"> Please <a class="external text" href="https://en.wikipedia.org/w/index.php?title=Foam&action=edit">help improve it</a> by rewriting it in an <a href="/wiki/Wikipedia:Writing_better_articles#Information_style_and_tone" title="Wikipedia:Writing better articles">encyclopedic style</a>.</span> <span class="date-container"><i>(<span class="date">August 2024</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> </div> </div><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:The_top_of_foamy_drink_(Unsplash).jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e2/The_top_of_foamy_drink_%28Unsplash%29.jpg/220px-The_top_of_foamy_drink_%28Unsplash%29.jpg" decoding="async" width="220" height="165" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e2/The_top_of_foamy_drink_%28Unsplash%29.jpg/330px-The_top_of_foamy_drink_%28Unsplash%29.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e2/The_top_of_foamy_drink_%28Unsplash%29.jpg/440px-The_top_of_foamy_drink_%28Unsplash%29.jpg 2x" data-file-width="4608" data-file-height="3456" /></a><figcaption>Top of a foamy drink</figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Foam_-_big.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/f/f4/Foam_-_big.jpg/220px-Foam_-_big.jpg" decoding="async" width="220" height="288" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/f4/Foam_-_big.jpg/330px-Foam_-_big.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/f4/Foam_-_big.jpg/440px-Foam_-_big.jpg 2x" data-file-width="1278" data-file-height="1675" /></a><figcaption><a href="/wiki/Soap" title="Soap">Soap</a> foam bubbles</figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Sponge-for-washing-1212612.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/7/79/Sponge-for-washing-1212612.jpg/220px-Sponge-for-washing-1212612.jpg" decoding="async" width="220" height="146" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/7/79/Sponge-for-washing-1212612.jpg/330px-Sponge-for-washing-1212612.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/7/79/Sponge-for-washing-1212612.jpg/440px-Sponge-for-washing-1212612.jpg 2x" data-file-width="4928" data-file-height="3264" /></a><figcaption>Cleaning sponge</figcaption></figure> <p><b>Foams</b> are two-phase <a href="/wiki/Materials_science" title="Materials science">material</a> systems where a gas is dispersed in a second, non-gaseous material, specifically, in which <a href="/wiki/Gas" title="Gas">gas</a> cells are enclosed by a distinct <a href="/wiki/Liquid" title="Liquid">liquid</a> or <a href="/wiki/Solid" title="Solid">solid</a> material.<sup id="cite_ref-WeaireHutzler1999_1-0" class="reference"><a href="#cite_note-WeaireHutzler1999-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Page / location: 6">: 6 </span></sup><sup id="cite_ref-Cantat_etal_1999_2-0" class="reference"><a href="#cite_note-Cantat_etal_1999-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Page / location: 4">: 4 </span></sup><sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> The foam "may contain more or less liquid [or solid] according to circumstances",<sup id="cite_ref-WeaireHutzler1999_1-1" class="reference"><a href="#cite_note-WeaireHutzler1999-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Page / location: 6">: 6 </span></sup> although in the case of gas-liquid foams, the gas occupies most of the volume.<sup id="cite_ref-Cantat_etal_1999_2-1" class="reference"><a href="#cite_note-Cantat_etal_1999-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Page / location: 4">: 4 </span></sup> The word derives from the <a href="/wiki/Old_High_German" title="Old High German">medieval German</a> and otherwise obsolete <i>veim</i>, in reference to the "frothy head forming in the glass once the beer has been freshly poured" (cf. <i>ausgefeimt</i>).<sup id="cite_ref-WeaireHutzler1999_1-2" class="reference"><a href="#cite_note-WeaireHutzler1999-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Page / location: 1">: 1 </span></sup> </p><p>Theories regarding foam formation, structure, and properties—in <a href="/wiki/Physics" title="Physics">physics</a> and <a href="/wiki/Physical_chemistry" title="Physical chemistry">physical chemistry</a>—differ somewhat between liquid and solid foams in that the former are dynamic (e.g., in their being "continuously deformed"), as a result of gas diffusing between cells, liquid draining from the foam into a bulk liquid, etc.<sup id="cite_ref-WeaireHutzler1999_1-3" class="reference"><a href="#cite_note-WeaireHutzler1999-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Page / location: 1–2">: 1–2 </span></sup> Theories regarding liquid foams have as direct analogs theories regarding <a href="/wiki/Emulsion" title="Emulsion">emulsions</a>,<sup id="cite_ref-WeaireHutzler1999_1-4" class="reference"><a href="#cite_note-WeaireHutzler1999-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Page / location: 3">: 3 </span></sup> two-phase <a href="/wiki/Materials_science" title="Materials science">material</a> systems in which one <a href="/wiki/Liquid" title="Liquid">liquid</a> is enclosed by another.<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> </p><p>In most foams, the volume of <a href="/wiki/Gas" title="Gas">gas</a> is large, with thin films of liquid or solid separating the regions of gas.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2024)">citation needed</span></a></i>]</sup> A <a href="/wiki/Sponge_(tool)" title="Sponge (tool)">bath sponge</a> and the <a href="/wiki/Beer_head" title="Beer head">head on a glass of beer</a> are examples of foams; soap foams are also known as <i>suds</i>.<sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources in the body of the article. (August 2024)">not verified in body</span></a></i>]</sup> </p><p>Solid foams can be closed-cell or <a href="/wiki/Reticulated_foam" title="Reticulated foam">open-cell</a>.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2024)">citation needed</span></a></i>]</sup> In closed-cell foam, the gas forms discrete pockets, each completely surrounded by the solid material. In open-cell foam, gas pockets connect to each other. A bath sponge is an example of an open-cell foam:<sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources in the body of the article. (August 2024)">not verified in body</span></a></i>]</sup> water easily flows through the entire structure, displacing the air. A <a href="/wiki/Sleeping_mat" class="mw-redirect" title="Sleeping mat">sleeping mat</a> is an example of a product composed of closed-cell foam.<sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources in the body of the article. (August 2024)">not verified in body</span></a></i>]</sup> </p><p>Foams are examples of <a href="/wiki/Dispersed_media" title="Dispersed media">dispersed media</a>.<sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources in the body of the article. (August 2024)">not verified in body</span></a></i>]</sup> In general, gas is present, so it divides into gas <a href="/wiki/Bubble_(physics)" title="Bubble (physics)">bubbles</a> of different sizes (i.e., the material is <a href="/wiki/Polydisperse" class="mw-redirect" title="Polydisperse">polydisperse</a><sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources in the body of the article. (August 2024)">not verified in body</span></a></i>]</sup>)—separated by liquid regions that may form films, thinner and thinner when the liquid phase drains out of the system <a href="/wiki/Interface_(chemistry)" class="mw-redirect" title="Interface (chemistry)">films</a>.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup><sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citing_sources" title="Wikipedia:Citing sources"><span title="This citation requires a reference to the specific page or range of pages in which the material appears. (August 2024)">page needed</span></a></i>]</sup> When the principal scale is small, i.e., for a very fine foam, this dispersed medium can be considered a type of <a href="/wiki/Colloid" title="Colloid">colloid</a>.<sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources in the body of the article. (August 2024)">not verified in body</span></a></i>]</sup> </p><p><i>Foam</i> can also refer to something that is analogous to foam, such as <a href="/wiki/Quantum_foam" title="Quantum foam">quantum foam</a>.<sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources in the body of the article. (August 2024)">not verified in body</span></a></i>]</sup> </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Structure">Structure</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=1" title="Edit section: Structure"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1251242444" /><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1248332772" /><table class="box-Multiple_issues plainlinks metadata ambox ambox-content ambox-multiple_issues compact-ambox" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/40px-Ambox_important.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/60px-Ambox_important.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/80px-Ambox_important.svg.png 2x" data-file-width="40" data-file-height="40" /></span></span></div></td><td class="mbox-text"><div class="mbox-text-span"><div class="multiple-issues-text mw-collapsible"><b>This section has multiple issues.</b> Please help <b><a href="/wiki/Special:EditPage/Foam" title="Special:EditPage/Foam">improve it</a></b> or discuss these issues on the <b><a href="/wiki/Talk:Foam" title="Talk:Foam">talk page</a></b>. <small><i>(<a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove these messages</a>)</i></small> <div class="mw-collapsible-content"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1251242444" /><table class="box-Expert_needed plainlinks metadata ambox ambox-content" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/40px-Ambox_important.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/60px-Ambox_important.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/80px-Ambox_important.svg.png 2x" data-file-width="40" data-file-height="40" /></span></span></div></td><td class="mbox-text"><div class="mbox-text-span">This section <b>needs attention from an expert in physics or chemistry</b>. The specific problem is: <b>the formal and key matter of defining what this form of material is, with distinction between liquid and solid foams, is not accomplished by the current unsourced essay.</b><span class="hide-when-compact"> <a href="/wiki/Wikipedia:WikiProject_Physics" title="Wikipedia:WikiProject Physics">WikiProject Physics</a> or <a href="/wiki/Wikipedia:WikiProject_Chemistry" title="Wikipedia:WikiProject Chemistry">WikiProject Chemistry</a> may be able to help recruit an expert.</span> <span class="date-container"><i>(<span class="date">August 2024</span>)</i></span></div></td></tr></tbody></table> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1251242444" /><table class="box-Essay-like plainlinks metadata ambox ambox-style ambox-essay-like" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/f/f2/Edit-clear.svg/40px-Edit-clear.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/f/f2/Edit-clear.svg/60px-Edit-clear.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/f/f2/Edit-clear.svg/80px-Edit-clear.svg.png 2x" data-file-width="48" data-file-height="48" /></span></span></div></td><td class="mbox-text"><div class="mbox-text-span">This section <b>is written like student essay summarising an unstated source</b> that states a Wikipedia editor's personal feelings or presents an original argument about a topic.<span class="hide-when-compact"> Please <a class="external text" href="https://en.wikipedia.org/w/index.php?title=Foam&action=edit">help improve it</a> by rewriting it in an <a href="/wiki/Wikipedia:Writing_better_articles#Information_style_and_tone" title="Wikipedia:Writing better articles">encyclopedic style</a>.</span> <span class="date-container"><i>(<span class="date">August 2024</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1251242444" /><table class="box-One_source plainlinks metadata ambox ambox-content ambox-one_source" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><a href="/wiki/File:Question_book-new.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png" decoding="async" width="50" height="39" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/75px-Question_book-new.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/100px-Question_book-new.svg.png 2x" data-file-width="512" data-file-height="399" /></a></span></div></td><td class="mbox-text"><div class="mbox-text-span">This section <b>relies largely or entirely on a <a href="/wiki/Wikipedia:Articles_with_a_single_source" title="Wikipedia:Articles with a single source">single source</a></b>.<span class="hide-when-compact"> Relevant discussion may be found on the <a href="/wiki/Talk:Foam" title="Talk:Foam">talk page</a>. Please help <a class="external text" href="https://en.wikipedia.org/w/index.php?title=Foam&action=edit">improve this article</a> by <a href="/wiki/Help:Referencing_for_beginners" title="Help:Referencing for beginners">introducing citations to additional sources</a>.<br /><small><span class="plainlinks"><i>Find sources:</i> <a rel="nofollow" class="external text" href="https://www.google.com/search?as_eq=wikipedia&q=%22Foam%22">"Foam"</a> – <a rel="nofollow" class="external text" href="https://www.google.com/search?tbm=nws&q=%22Foam%22+-wikipedia&tbs=ar:1">news</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?&q=%22Foam%22&tbs=bkt:s&tbm=bks">newspapers</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?tbs=bks:1&q=%22Foam%22+-wikipedia">books</a> <b>·</b> <a rel="nofollow" class="external text" href="https://scholar.google.com/scholar?q=%22Foam%22">scholar</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.jstor.org/action/doBasicSearch?Query=%22Foam%22&acc=on&wc=on">JSTOR</a></span></small></span> <span class="date-container"><i>(<span class="date">August 2024</span>)</i></span></div></td></tr></tbody></table> </div> </div><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <p>A foam is, in many cases, a multi-scale system.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2024)">citation needed</span></a></i>]</sup> </p> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Order_and_Chaos.tif" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Order_and_Chaos.tif/lossy-page1-220px-Order_and_Chaos.tif.jpg" decoding="async" width="220" height="135" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Order_and_Chaos.tif/lossy-page1-330px-Order_and_Chaos.tif.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Order_and_Chaos.tif/lossy-page1-440px-Order_and_Chaos.tif.jpg 2x" data-file-width="2350" data-file-height="1445" /></a><figcaption>Order and disorder of bubbles in a surface foam</figcaption></figure> <p>One scale is the bubble: <a href="/wiki/Materials_science" title="Materials science">material</a> foams are typically <a href="/wiki/Randomness" title="Randomness">disordered</a> and have a variety of bubble sizes.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2024)">citation needed</span></a></i>]</sup> At larger sizes, the study of idealized foams is closely linked to the mathematical problems of <a href="/wiki/Minimal_surface" title="Minimal surface">minimal surfaces</a> and three-dimensional <a href="/wiki/Tessellations" class="mw-redirect" title="Tessellations">tessellations</a>, also called <a href="/wiki/Honeycomb_(geometry)" title="Honeycomb (geometry)">honeycombs</a>.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2024)">citation needed</span></a></i>]</sup> The <a href="/wiki/Weaire%E2%80%93Phelan_structure" title="Weaire–Phelan structure">Weaire–Phelan structure</a> is reported in one primary philosophical source to be the best possible (optimal) <a href="/wiki/Unit_cell" title="Unit cell">unit cell</a> of a perfectly ordered foam,<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup><sup class="noprint Inline-Template noprint noexcerpt Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:NOTRS" class="mw-redirect" title="Wikipedia:NOTRS"><span title="This claim needs references to better sources. (August 2024)">better source needed</span></a></i>]</sup> while <a href="/wiki/Plateau%27s_laws" title="Plateau's laws">Plateau's laws</a> describe how soap-films form structures in foams.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2024)">citation needed</span></a></i>]</sup> </p><p>At lower scale than the bubble is the thickness of the film for <a href="/wiki/Metastable" class="mw-redirect" title="Metastable">metastable</a> foams, which can be considered a network of interconnected films called <a href="/wiki/Lamella_(materials)" title="Lamella (materials)">lamellae</a>. <sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2024)">citation needed</span></a></i>]</sup> Ideally, the lamellae connect in triads and radiate 120° outward from the connection points,<sup class="noprint Inline-Template" style="margin-left:0.1em; white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Manual_of_Style/Words_to_watch#Unsupported_attributions" title="Wikipedia:Manual of Style/Words to watch"><span title="The material near this tag may use weasel words or too-vague attribution. (August 2024)">according to whom?</span></a></i>]</sup> known as <a href="/wiki/Plateau%27s_laws" title="Plateau's laws">Plateau borders</a>. <sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2024)">citation needed</span></a></i>]</sup> </p><p>An even lower scale is the liquid–air interface at the surface of the film.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2024)">citation needed</span></a></i>]</sup> Most of the time this interface is stabilized by a layer of <a href="/wiki/Amphiphilic" class="mw-redirect" title="Amphiphilic">amphiphilic</a> structure, often made of <a href="/wiki/Surfactant" title="Surfactant">surfactants</a>, particles (<a href="/wiki/Pickering_emulsion" title="Pickering emulsion">Pickering emulsion</a>), or more complex associations.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2024)">citation needed</span></a></i>]</sup> </p> <div class="mw-heading mw-heading2"><h2 id="Formation">Formation</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=2" title="Edit section: Formation"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1251242444" /><table class="box-More_citations_needed_section plainlinks metadata ambox ambox-content ambox-Refimprove" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><a href="/wiki/File:Question_book-new.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png" decoding="async" width="50" height="39" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/75px-Question_book-new.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/100px-Question_book-new.svg.png 2x" data-file-width="512" data-file-height="399" /></a></span></div></td><td class="mbox-text"><div class="mbox-text-span">This section <b>needs additional citations for <a href="/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">verification</a></b>.<span class="hide-when-compact"> Please help <a href="/wiki/Special:EditPage/Foam" title="Special:EditPage/Foam">improve this article</a> by <a href="/wiki/Help:Referencing_for_beginners" title="Help:Referencing for beginners">adding citations to reliable sources</a> in this section. Unsourced material may be challenged and removed.</span> <span class="date-container"><i>(<span class="date">August 2024</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <p>Several conditions are needed to produce foam: there must be mechanical work, <a href="/wiki/Surfactant" title="Surfactant">surface active components</a> (surfactants) that reduce the <a href="/wiki/Surface_tension" title="Surface tension">surface tension</a>, and the formation of foam faster than its breakdown. To create foam, <a href="/wiki/Work_(physics)" title="Work (physics)">work</a> (W) is needed to increase the <a href="/wiki/Surface_area" title="Surface area">surface area</a> (ΔA): </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle W=\gamma \Delta A\,\!}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>W</mi> <mo>=</mo> <mi>γ</mi> <mi mathvariant="normal">Δ</mi> <mi>A</mi> <mspace width="thinmathspace"></mspace> <mspace width="negativethinmathspace"></mspace> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle W=\gamma \Delta A\,\!}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/681a3423d5bedb57a6fe038a75e134254ff27498" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; margin-right: -0.387ex; width:10.862ex; height:2.676ex;" alt="{\displaystyle W=\gamma \Delta A\,\!}" /></span></dd></dl> <p>where γ is the surface tension. </p><p>One of the ways foam is created is through dispersion, where a large amount of gas is mixed with a liquid. A more specific method of dispersion involves injecting a gas through a hole in a solid into a liquid. If this process is completed very slowly, then one bubble can be emitted from the orifice at a time as shown in the picture below. </p><p>One of the theories for determining the separation time is shown below; however, while this theory produces theoretical data that matches the experimental data, detachment due to capillarity is accepted as a better explanation. </p> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Rising_Bubble_from_Orifice.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/6/6e/Rising_Bubble_from_Orifice.png/250px-Rising_Bubble_from_Orifice.png" decoding="async" width="220" height="219" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/6/6e/Rising_Bubble_from_Orifice.png 1.5x" data-file-width="260" data-file-height="259" /></a><figcaption>Rising bubble from orifice</figcaption></figure> <p>The <a href="/wiki/Buoyancy" title="Buoyancy">buoyancy</a> force acts to raise the bubble, which is </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle F_{b}=Vg(\rho _{2}-\rho _{1})\!}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>F</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>b</mi> </mrow> </msub> <mo>=</mo> <mi>V</mi> <mi>g</mi> <mo stretchy="false">(</mo> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> <mo>−</mo> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> <mo stretchy="false">)</mo> <mspace width="negativethinmathspace"></mspace> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle F_{b}=Vg(\rho _{2}-\rho _{1})\!}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/a839022cd75aed4bfd31b1bdc69116a1fc6fec00" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; margin-right: -0.166ex; width:17.375ex; height:2.843ex;" alt="{\displaystyle F_{b}=Vg(\rho _{2}-\rho _{1})\!}" /></span></dd></dl> <p>where <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle V}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>V</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle V}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/af0f6064540e84211d0ffe4dac72098adfa52845" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.787ex; height:2.176ex;" alt="{\displaystyle V}" /></span> is the volume of the bubble, <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle g}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>g</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle g}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/d3556280e66fe2c0d0140df20935a6f057381d77" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.116ex; height:2.009ex;" alt="{\displaystyle g}" /></span> is the acceleration due to gravity, and ρ<sub>1</sub> is the density of the gas ρ<sub>2</sub> is the density of the liquid. The force working against the buoyancy force is the <a href="/wiki/Surface_tension" title="Surface tension">surface tension</a> force, which is </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle F_{s}=2r\pi \gamma \!}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>F</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>s</mi> </mrow> </msub> <mo>=</mo> <mn>2</mn> <mi>r</mi> <mi>π</mi> <mi>γ</mi> <mspace width="negativethinmathspace"></mspace> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle F_{s}=2r\pi \gamma \!}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/40e5a30dc1c80099e54b1ed8ad5e7b218ed24601" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; margin-right: -0.387ex; width:10.402ex; height:2.676ex;" alt="{\displaystyle F_{s}=2r\pi \gamma \!}" /></span>,</dd></dl> <p>where γ is the surface tension, and <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle r}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>r</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle r}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/0d1ecb613aa2984f0576f70f86650b7c2a132538" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.049ex; height:1.676ex;" alt="{\displaystyle r}" /></span> is the radius of the orifice. As more air is pushed into the bubble, the buoyancy force grows quicker than the surface tension force. Thus, detachment occurs when the buoyancy force is large enough to overcome the surface tension force. </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle Vg(\rho _{2}-\rho _{1})>2r\pi \gamma \!}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>V</mi> <mi>g</mi> <mo stretchy="false">(</mo> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> <mo>−</mo> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> <mo stretchy="false">)</mo> <mo>></mo> <mn>2</mn> <mi>r</mi> <mi>π</mi> <mi>γ</mi> <mspace width="negativethinmathspace"></mspace> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle Vg(\rho _{2}-\rho _{1})>2r\pi \gamma \!}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/9ff9ca3a07d2768e0eca0cfacb895cc13dc9ede2" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; margin-right: -0.387ex; width:19.969ex; height:2.843ex;" alt="{\displaystyle Vg(\rho _{2}-\rho _{1})>2r\pi \gamma \!}" /></span></dd></dl> <p>In addition, if the bubble is treated as a sphere with a radius of <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle R}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>R</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle R}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/4b0bfb3769bf24d80e15374dc37b0441e2616e33" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.764ex; height:2.176ex;" alt="{\displaystyle R}" /></span> and the volume <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle V}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>V</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle V}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/af0f6064540e84211d0ffe4dac72098adfa52845" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.787ex; height:2.176ex;" alt="{\displaystyle V}" /></span> is substituted in to the equation above, separation occurs at the moment when </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle R^{3}={\frac {3r\gamma }{2g(\rho _{2}-\rho _{1})}}\!}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msup> <mi>R</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>3</mn> </mrow> </msup> <mo>=</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mrow> <mn>3</mn> <mi>r</mi> <mi>γ</mi> </mrow> <mrow> <mn>2</mn> <mi>g</mi> <mo stretchy="false">(</mo> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> <mo>−</mo> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> <mo stretchy="false">)</mo> </mrow> </mfrac> </mrow> <mspace width="negativethinmathspace"></mspace> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle R^{3}={\frac {3r\gamma }{2g(\rho _{2}-\rho _{1})}}\!}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/87cc79fcd606f37cc1d963bf3a9a93a8711278ef" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.671ex; margin-right: -0.108ex; width:17.915ex; height:6.176ex;" alt="{\displaystyle R^{3}={\frac {3r\gamma }{2g(\rho _{2}-\rho _{1})}}\!}" /></span></dd></dl> <p>Examining this phenomenon from a capillarity viewpoint for a bubble that is being formed very slowly, it can be assumed that the pressure <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>p</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle p}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/81eac1e205430d1f40810df36a0edffdc367af36" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.089ex; width:1.259ex; height:2.009ex;" alt="{\displaystyle p}" /></span> inside is constant everywhere. The hydrostatic pressure in the liquid is designated by <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p_{0}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>p</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>0</mn> </mrow> </msub> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle p_{0}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/2b969ada68a88e2aeba9a2d2096abaf1fd53c21d" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.089ex; width:2.313ex; height:2.009ex;" alt="{\displaystyle p_{0}}" /></span>. The change in pressure across the interface from gas to liquid is equal to the capillary pressure; hence, </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p-p_{0}=\gamma \left({\frac {1}{R_{1}}}+{\frac {1}{R_{2}}}\right)\!}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>p</mi> <mo>−</mo> <msub> <mi>p</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>0</mn> </mrow> </msub> <mo>=</mo> <mi>γ</mi> <mrow> <mo>(</mo> <mrow> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mn>1</mn> <msub> <mi>R</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> </mfrac> </mrow> <mo>+</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mn>1</mn> <msub> <mi>R</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> </mfrac> </mrow> </mrow> <mo>)</mo> </mrow> <mspace width="negativethinmathspace"></mspace> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle p-p_{0}=\gamma \left({\frac {1}{R_{1}}}+{\frac {1}{R_{2}}}\right)\!}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/3408ab897b63ff9ea322f2b65277ecf5e7b6b480" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.505ex; margin-left: -0.089ex; width:24.254ex; height:6.176ex;" alt="{\displaystyle p-p_{0}=\gamma \left({\frac {1}{R_{1}}}+{\frac {1}{R_{2}}}\right)\!}" /></span></dd></dl> <p>where R<sub>1</sub> and R<sub>2</sub> are the radii of curvature and are set as positive. At the stem of the bubble, R<sub>3</sub> and R<sub>4</sub> are the radii of curvature also treated as positive. Here the hydrostatic pressure in the liquid has to take into account z, the distance from the top to the stem of the bubble. The new hydrostatic pressure at the stem of the bubble is <i>p</i><sub>0</sub>(<i>ρ</i><sub>1</sub> − <i>ρ</i><sub>2</sub>)<i>z</i>. The hydrostatic pressure balances the capillary pressure, which is shown below: </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p-p_{0}-(\rho _{2}-\rho _{1})gz=\gamma \left({\frac {1}{R_{3}}}+{\frac {1}{R_{4}}}\right)\!}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>p</mi> <mo>−</mo> <msub> <mi>p</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>0</mn> </mrow> </msub> <mo>−</mo> <mo stretchy="false">(</mo> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> <mo>−</mo> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> <mo stretchy="false">)</mo> <mi>g</mi> <mi>z</mi> <mo>=</mo> <mi>γ</mi> <mrow> <mo>(</mo> <mrow> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mn>1</mn> <msub> <mi>R</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>3</mn> </mrow> </msub> </mfrac> </mrow> <mo>+</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mn>1</mn> <msub> <mi>R</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>4</mn> </mrow> </msub> </mfrac> </mrow> </mrow> <mo>)</mo> </mrow> <mspace width="negativethinmathspace"></mspace> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle p-p_{0}-(\rho _{2}-\rho _{1})gz=\gamma \left({\frac {1}{R_{3}}}+{\frac {1}{R_{4}}}\right)\!}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/c3d067d06577a07c4d40ab06537ecf914e46bbab" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.505ex; margin-left: -0.089ex; width:38.461ex; height:6.176ex;" alt="{\displaystyle p-p_{0}-(\rho _{2}-\rho _{1})gz=\gamma \left({\frac {1}{R_{3}}}+{\frac {1}{R_{4}}}\right)\!}" /></span></dd></dl> <p>Finally, the difference in the top and bottom pressure equals the change in hydrostatic pressure: </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle (\rho _{2}-\rho _{1})gz=\gamma \left({\frac {1}{R_{1}}}+{\frac {1}{R_{2}}}-{\frac {1}{R_{3}}}-{\frac {1}{R_{4}}}\right)\!}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mo stretchy="false">(</mo> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> <mo>−</mo> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> <mo stretchy="false">)</mo> <mi>g</mi> <mi>z</mi> <mo>=</mo> <mi>γ</mi> <mrow> <mo>(</mo> <mrow> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mn>1</mn> <msub> <mi>R</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> </mfrac> </mrow> <mo>+</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mn>1</mn> <msub> <mi>R</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> </mfrac> </mrow> <mo>−</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mn>1</mn> <msub> <mi>R</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>3</mn> </mrow> </msub> </mfrac> </mrow> <mo>−</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mn>1</mn> <msub> <mi>R</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>4</mn> </mrow> </msub> </mfrac> </mrow> </mrow> <mo>)</mo> </mrow> <mspace width="negativethinmathspace"></mspace> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle (\rho _{2}-\rho _{1})gz=\gamma \left({\frac {1}{R_{1}}}+{\frac {1}{R_{2}}}-{\frac {1}{R_{3}}}-{\frac {1}{R_{4}}}\right)\!}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/43c1535ebfe428d5e42d44513f16de8d5a44727d" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.505ex; width:42.287ex; height:6.176ex;" alt="{\displaystyle (\rho _{2}-\rho _{1})gz=\gamma \left({\frac {1}{R_{1}}}+{\frac {1}{R_{2}}}-{\frac {1}{R_{3}}}-{\frac {1}{R_{4}}}\right)\!}" /></span></dd></dl> <p>At the stem of the bubble, the shape of the bubble is nearly cylindrical; consequently, either R<sub>3</sub> or R<sub>4</sub> is large while the other radius of curvature is small. As the stem of the bubble grows in length, it becomes more unstable as one of the radius grows and the other shrinks. At a certain point, the vertical length of the stem exceeds the circumference of the stem and due to the buoyancy forces the bubble separates and the process repeats.<sup id="cite_ref-autogenerated1_7-0" class="reference"><a href="#cite_note-autogenerated1-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Stability">Stability</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=3" title="Edit section: Stability"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1251242444" /><table class="box-More_citations_needed_section plainlinks metadata ambox ambox-content ambox-Refimprove" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><a href="/wiki/File:Question_book-new.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png" decoding="async" width="50" height="39" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/75px-Question_book-new.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/100px-Question_book-new.svg.png 2x" data-file-width="512" data-file-height="399" /></a></span></div></td><td class="mbox-text"><div class="mbox-text-span">This section <b>needs additional citations for <a href="/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">verification</a></b>.<span class="hide-when-compact"> Please help <a href="/wiki/Special:EditPage/Foam" title="Special:EditPage/Foam">improve this article</a> by <a href="/wiki/Help:Referencing_for_beginners" title="Help:Referencing for beginners">adding citations to reliable sources</a> in this section. Unsourced material may be challenged and removed.</span> <span class="date-container"><i>(<span class="date">August 2024</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <div class="mw-heading mw-heading3"><h3 id="Stabilization">Stabilization</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=4" title="Edit section: Stabilization"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1273380762/mw-parser-output/.tmulti">.mw-parser-output .tmulti .multiimageinner{display:flex;flex-direction:column}.mw-parser-output .tmulti .trow{display:flex;flex-direction:row;clear:left;flex-wrap:wrap;width:100%;box-sizing:border-box}.mw-parser-output .tmulti .tsingle{margin:1px;float:left}.mw-parser-output .tmulti .theader{clear:both;font-weight:bold;text-align:center;align-self:center;background-color:transparent;width:100%}.mw-parser-output .tmulti .thumbcaption{background-color:transparent}.mw-parser-output .tmulti .text-align-left{text-align:left}.mw-parser-output .tmulti .text-align-right{text-align:right}.mw-parser-output .tmulti .text-align-center{text-align:center}@media all and (max-width:720px){.mw-parser-output .tmulti .thumbinner{width:100%!important;box-sizing:border-box;max-width:none!important;align-items:center}.mw-parser-output .tmulti .trow{justify-content:center}.mw-parser-output .tmulti .tsingle{float:none!important;max-width:100%!important;box-sizing:border-box;text-align:center}.mw-parser-output .tmulti .tsingle .thumbcaption{text-align:left}.mw-parser-output .tmulti .trow>.thumbcaption{text-align:center}}@media screen{html.skin-theme-clientpref-night .mw-parser-output .tmulti .multiimageinner span:not(.skin-invert-image):not(.skin-invert):not(.bg-transparent) img{background-color:white}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .tmulti .multiimageinner span:not(.skin-invert-image):not(.skin-invert):not(.bg-transparent) img{background-color:white}}</style><div class="thumb tmulti tright"><div class="thumbinner multiimageinner" style="width:224px;max-width:224px"><div class="trow"><div class="tsingle" style="width:222px;max-width:222px"><div class="thumbimage"><span typeof="mw:File"><a href="/wiki/File:Marangoni_Effect_of_a_Film.png" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/2/26/Marangoni_Effect_of_a_Film.png/250px-Marangoni_Effect_of_a_Film.png" decoding="async" width="220" height="95" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/26/Marangoni_Effect_of_a_Film.png/330px-Marangoni_Effect_of_a_Film.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/26/Marangoni_Effect_of_a_Film.png/440px-Marangoni_Effect_of_a_Film.png 2x" data-file-width="488" data-file-height="210" /></a></span></div><div class="thumbcaption">Marangoni effect of a film</div></div></div><div class="trow"><div class="tsingle" style="width:222px;max-width:222px"><div class="thumbimage"><span typeof="mw:File"><a href="/wiki/File:Marangoni_Effect_of_a_film_(2).png" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/4/42/Marangoni_Effect_of_a_film_%282%29.png/250px-Marangoni_Effect_of_a_film_%282%29.png" decoding="async" width="220" height="92" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/42/Marangoni_Effect_of_a_film_%282%29.png/330px-Marangoni_Effect_of_a_film_%282%29.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/42/Marangoni_Effect_of_a_film_%282%29.png/440px-Marangoni_Effect_of_a_film_%282%29.png 2x" data-file-width="494" data-file-height="207" /></a></span></div><div class="thumbcaption">Marangoni effect of a film (2)</div></div></div></div></div> <p>The stabilization of foam is caused by <a href="/wiki/Van_der_Waals_force" title="Van der Waals force">van der Waals forces</a> between the molecules in the foam, <a href="/wiki/Electrical_double_layer" class="mw-redirect" title="Electrical double layer">electrical double layers</a> created by <a href="/wiki/Dipole" title="Dipole">dipolar</a> surfactants, and the <a href="/wiki/Marangoni_effect" title="Marangoni effect">Marangoni effect</a>, which acts as a restoring force to the lamellae. </p><p>The Marangoni effect depends on the liquid that is foaming being impure. Generally, surfactants in the solution decrease the surface tension. The surfactants also clump together on the surface and form a layer as shown below. </p><p>For the Marangoni effect to occur, the foam must be indented as shown in the first picture. This indentation increases the local surface area. Surfactants have a larger diffusion time than the bulk of the solution—so the surfactants are less concentrated in the indentation. </p><p>Also, surface stretching makes the surface tension of the indented spot greater than the surrounding area. Consequentially—since the diffusion time for the surfactants is large—the Marangoni effect has time to take place. The difference in surface tension creates a gradient, which instigates fluid flow from areas of lower surface tension to areas of higher surface tension. The second picture shows the film at equilibrium after the Marangoni effect has taken place.<sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> </p><p><a href="/wiki/Curing_(chemistry)" title="Curing (chemistry)">Curing</a> a foam solidifies it, making it indefinitely stable at STP.<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Destabilization">Destabilization</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=5" title="Edit section: Destabilization"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Witold Rybczynski and Jacques Hadamard developed an equation to calculate the velocity of bubbles that rise in foam with the assumption that the bubbles are spherical with a radius <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle r}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>r</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle r}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/0d1ecb613aa2984f0576f70f86650b7c2a132538" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.049ex; height:1.676ex;" alt="{\displaystyle r}" /></span>. </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle u={\frac {2gr^{2}}{9\eta _{2}}}(\rho _{2}-\rho _{1})\left({\frac {3\eta _{1}+3\eta _{2}}{3\eta _{1}+2\eta _{2}}}\right)\!}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>u</mi> <mo>=</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mrow> <mn>2</mn> <mi>g</mi> <msup> <mi>r</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msup> </mrow> <mrow> <mn>9</mn> <msub> <mi>η</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> </mrow> </mfrac> </mrow> <mo stretchy="false">(</mo> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> <mo>−</mo> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> <mo stretchy="false">)</mo> <mrow> <mo>(</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mrow> <mn>3</mn> <msub> <mi>η</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> <mo>+</mo> <mn>3</mn> <msub> <mi>η</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> </mrow> <mrow> <mn>3</mn> <msub> <mi>η</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> <mo>+</mo> <mn>2</mn> <msub> <mi>η</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> </mrow> </mfrac> </mrow> <mo>)</mo> </mrow> <mspace width="negativethinmathspace"></mspace> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle u={\frac {2gr^{2}}{9\eta _{2}}}(\rho _{2}-\rho _{1})\left({\frac {3\eta _{1}+3\eta _{2}}{3\eta _{1}+2\eta _{2}}}\right)\!}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/08e31a3978a8fa982395889cc2aa047bc586c49c" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.505ex; width:32.65ex; height:6.343ex;" alt="{\displaystyle u={\frac {2gr^{2}}{9\eta _{2}}}(\rho _{2}-\rho _{1})\left({\frac {3\eta _{1}+3\eta _{2}}{3\eta _{1}+2\eta _{2}}}\right)\!}" /></span></dd></dl> <p>with velocity in units of centimeters per second. ρ<sub>1</sub> and ρ<sub>2</sub> is the density for a gas and liquid respectively in units of g/cm<sup>3</sup> and ῃ<sub>1</sub> and ῃ<sub>2</sub> is the <a href="/wiki/Viscosity#Dynamic_viscosity" title="Viscosity"> dynamic viscosity</a> of the gas and liquid respectively in units of g/cm·s and g is the <a href="/wiki/Gravitational_acceleration" title="Gravitational acceleration"> acceleration of gravity</a> in units of cm/s<sup>2</sup>. </p><p>However, since the density and viscosity of a liquid is much greater than the gas, the density and viscosity of the gas can be neglected, which yields the new equation for velocity of bubbles rising as: </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle u={\frac {gr^{2}}{3\eta _{2}}}(\rho _{2})\!}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>u</mi> <mo>=</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mrow> <mi>g</mi> <msup> <mi>r</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msup> </mrow> <mrow> <mn>3</mn> <msub> <mi>η</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> </mrow> </mfrac> </mrow> <mo stretchy="false">(</mo> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> <mo stretchy="false">)</mo> <mspace width="negativethinmathspace"></mspace> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle u={\frac {gr^{2}}{3\eta _{2}}}(\rho _{2})\!}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/216e0b4161f622296b8b02e44ffb01621aed413e" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.338ex; margin-right: -0.166ex; width:12.481ex; height:6.176ex;" alt="{\displaystyle u={\frac {gr^{2}}{3\eta _{2}}}(\rho _{2})\!}" /></span></dd></dl> <p>However, through experiments it has been shown that a more accurate model for bubbles rising is: </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle u={\frac {2gr^{2}}{9\eta _{2}}}(\rho _{2}-\rho _{1})\!}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>u</mi> <mo>=</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mrow> <mn>2</mn> <mi>g</mi> <msup> <mi>r</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msup> </mrow> <mrow> <mn>9</mn> <msub> <mi>η</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> </mrow> </mfrac> </mrow> <mo stretchy="false">(</mo> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> <mo>−</mo> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> <mo stretchy="false">)</mo> <mspace width="negativethinmathspace"></mspace> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle u={\frac {2gr^{2}}{9\eta _{2}}}(\rho _{2}-\rho _{1})\!}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/abbbe566c999b89c68c3c5803cb93d42ea92cb55" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.338ex; margin-right: -0.166ex; width:18.587ex; height:6.176ex;" alt="{\displaystyle u={\frac {2gr^{2}}{9\eta _{2}}}(\rho _{2}-\rho _{1})\!}" /></span></dd></dl> <p>Deviations are due to the <a href="/wiki/Marangoni_effect" title="Marangoni effect">Marangoni effect</a> and capillary pressure, which affect the assumption that the bubbles are spherical. For laplace pressure of a curved gas liquid interface, the two principal radii of curvature at a point are R<sub>1</sub> and R<sub>2</sub>.<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> With a curved interface, the pressure in one phase is greater than the pressure in another phase. The capillary pressure P<sub>c</sub> is given by the equation of: </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle P_{c}=\gamma \left({\frac {1}{R_{1}}}+{\frac {1}{R_{2}}}\right)\!}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>P</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>c</mi> </mrow> </msub> <mo>=</mo> <mi>γ</mi> <mrow> <mo>(</mo> <mrow> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mn>1</mn> <msub> <mi>R</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> </mfrac> </mrow> <mo>+</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mn>1</mn> <msub> <mi>R</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> </mfrac> </mrow> </mrow> <mo>)</mo> </mrow> <mspace width="negativethinmathspace"></mspace> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle P_{c}=\gamma \left({\frac {1}{R_{1}}}+{\frac {1}{R_{2}}}\right)\!}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/b9498c1fed0764bc1321d4df09ad7af9192f7169" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.505ex; width:20.368ex; height:6.176ex;" alt="{\displaystyle P_{c}=\gamma \left({\frac {1}{R_{1}}}+{\frac {1}{R_{2}}}\right)\!}" /></span>,</dd></dl> <p>where <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \gamma }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>γ</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \gamma }</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/a223c880b0ce3da8f64ee33c4f0010beee400b1a" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:1.262ex; height:2.176ex;" alt="{\displaystyle \gamma }" /></span> is the surface tension. The bubble shown below is a gas (phase 1) in a liquid (phase 2) and point A designates the top of the bubble while point B designates the bottom of the bubble. </p> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Bubble_for_Hydrostatic_Pressure.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/3/3e/Bubble_for_Hydrostatic_Pressure.svg/220px-Bubble_for_Hydrostatic_Pressure.svg.png" decoding="async" width="220" height="212" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/3/3e/Bubble_for_Hydrostatic_Pressure.svg/330px-Bubble_for_Hydrostatic_Pressure.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/3/3e/Bubble_for_Hydrostatic_Pressure.svg/440px-Bubble_for_Hydrostatic_Pressure.svg.png 2x" data-file-width="512" data-file-height="493" /></a><figcaption>Bubble for hydrostatic pressure</figcaption></figure> <p>At the top of the bubble at point A, the pressure in the liquid is assumed to be p<sub>0</sub> as well as in the gas. At the bottom of the bubble at point B, the hydrostatic pressure is: </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle P_{B},1=p_{0}+g\rho _{1}z\!}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>P</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>B</mi> </mrow> </msub> <mo>,</mo> <mn>1</mn> <mo>=</mo> <msub> <mi>p</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>0</mn> </mrow> </msub> <mo>+</mo> <mi>g</mi> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> <mi>z</mi> <mspace width="negativethinmathspace"></mspace> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle P_{B},1=p_{0}+g\rho _{1}z\!}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/911e2ed10fa20294b836df96fb8ee9b073aeed79" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; margin-right: -0.387ex; width:17.791ex; height:2.676ex;" alt="{\displaystyle P_{B},1=p_{0}+g\rho _{1}z\!}" /></span></dd> <dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle P_{B},2=p_{0}+g\rho _{2}z\!}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>P</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>B</mi> </mrow> </msub> <mo>,</mo> <mn>2</mn> <mo>=</mo> <msub> <mi>p</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>0</mn> </mrow> </msub> <mo>+</mo> <mi>g</mi> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> <mi>z</mi> <mspace width="negativethinmathspace"></mspace> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle P_{B},2=p_{0}+g\rho _{2}z\!}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/9903e1196fce6557ea50abf4da266bed58fc6961" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; margin-right: -0.387ex; width:17.791ex; height:2.676ex;" alt="{\displaystyle P_{B},2=p_{0}+g\rho _{2}z\!}" /></span></dd></dl> <p>where ρ<sub>1</sub> and ρ<sub>2</sub> is the density for a gas and liquid respectively. The difference in hydrostatic pressure at the top of the bubble is 0, while the difference in hydrostatic pressure at the bottom of the bubble across the interface is <i>gz</i>(<i>ρ</i><sub>2</sub> − <i>ρ</i><sub>1</sub>). Assuming that the radii of curvature at point A are equal and denoted by R<sub>A</sub> and that the radii of curvature at point B are equal and denoted by R<sub>B</sub>, then the difference in capillary pressure between point A and point B is: </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle P_{c}=2\gamma \left({\frac {1}{R_{A}}}-{\frac {1}{R_{B}}}\right)\!}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>P</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>c</mi> </mrow> </msub> <mo>=</mo> <mn>2</mn> <mi>γ</mi> <mrow> <mo>(</mo> <mrow> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mn>1</mn> <msub> <mi>R</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>A</mi> </mrow> </msub> </mfrac> </mrow> <mo>−</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mn>1</mn> <msub> <mi>R</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>B</mi> </mrow> </msub> </mfrac> </mrow> </mrow> <mo>)</mo> </mrow> <mspace width="negativethinmathspace"></mspace> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle P_{c}=2\gamma \left({\frac {1}{R_{A}}}-{\frac {1}{R_{B}}}\right)\!}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/5b38d716cda0fa5db998345e0ce026cd9079c4c6" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.505ex; width:22.366ex; height:6.176ex;" alt="{\displaystyle P_{c}=2\gamma \left({\frac {1}{R_{A}}}-{\frac {1}{R_{B}}}\right)\!}" /></span></dd></dl> <p>At equilibrium, the difference in capillary pressure must be balanced by the difference in hydrostatic pressure. Hence, </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle gz(\rho _{2}-\rho _{1})=2\gamma \left({\frac {1}{R_{A}}}-{\frac {1}{R_{B}}}\right)\!}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>g</mi> <mi>z</mi> <mo stretchy="false">(</mo> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> <mo>−</mo> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> <mo stretchy="false">)</mo> <mo>=</mo> <mn>2</mn> <mi>γ</mi> <mrow> <mo>(</mo> <mrow> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mn>1</mn> <msub> <mi>R</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>A</mi> </mrow> </msub> </mfrac> </mrow> <mo>−</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mn>1</mn> <msub> <mi>R</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>B</mi> </mrow> </msub> </mfrac> </mrow> </mrow> <mo>)</mo> </mrow> <mspace width="negativethinmathspace"></mspace> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle gz(\rho _{2}-\rho _{1})=2\gamma \left({\frac {1}{R_{A}}}-{\frac {1}{R_{B}}}\right)\!}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/b8396ef81d90e71e03d85071f8ffc8b23c89f3e3" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.505ex; width:31.296ex; height:6.176ex;" alt="{\displaystyle gz(\rho _{2}-\rho _{1})=2\gamma \left({\frac {1}{R_{A}}}-{\frac {1}{R_{B}}}\right)\!}" /></span></dd></dl> <p>Since, the density of the gas is less than the density of the liquid the left hand side of the equation is always positive. Therefore, the inverse of R<sub>A</sub> must be larger than the R<sub>B</sub>. Meaning that from the top of the bubble to the bottom of the bubble the radius of curvature increases. Therefore, without neglecting gravity the bubbles cannot be spherical. In addition, as z increases, this causes the difference in R<sub>A</sub> and R<sub>B</sub> too, which means the bubble deviates more from its shape the larger it grows.<sup id="cite_ref-autogenerated1_7-1" class="reference"><a href="#cite_note-autogenerated1-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> </p><p>Foam destabilization occurs for several reasons. First, <a href="/wiki/Gravitation" class="mw-redirect" title="Gravitation">gravitation</a> causes drainage of liquid to the foam base, which Rybczynski and Hadamar include in their theory; however, foam also destabilizes due to <a href="/wiki/Osmotic_pressure" title="Osmotic pressure">osmotic pressure</a> causes drainage from the lamellas to the Plateau borders due to internal concentration differences in the foam, and <a href="/wiki/Laplace_pressure" title="Laplace pressure">Laplace pressure</a> causes diffusion of gas from small to large bubbles due to pressure difference. In addition, films can break under <a href="/wiki/Disjoining_pressure" title="Disjoining pressure">disjoining pressure</a>, These effects can lead to rearrangement of the foam structure at scales larger than the bubbles, which may be individual (<a href="/wiki/T1_process" title="T1 process">T1 process</a>) or collective (even of the "avalanche" type). </p> <div class="mw-heading mw-heading2"><h2 id="Mechanical_properties">Mechanical properties</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=6" title="Edit section: Mechanical properties"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Liquid_foams">Liquid foams</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=7" title="Edit section: Liquid foams"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1251242444" /><table class="box-Expand_section plainlinks metadata ambox ambox-content" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><a href="/wiki/File:Wiki_letter_w_cropped.svg" class="mw-file-description"><img alt="[icon]" src="//upload.wikimedia.org/wikipedia/commons/thumb/1/1c/Wiki_letter_w_cropped.svg/44px-Wiki_letter_w_cropped.svg.png" decoding="async" width="44" height="31" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/1c/Wiki_letter_w_cropped.svg/66px-Wiki_letter_w_cropped.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/1c/Wiki_letter_w_cropped.svg/88px-Wiki_letter_w_cropped.svg.png 2x" data-file-width="44" data-file-height="31" /></a></span></div></td><td class="mbox-text"><div class="mbox-text-span">This section <b>needs expansion</b> with: as thorough a treatment as is included in the solid foam subsection. You can help by <a class="external text" href="https://en.wikipedia.org/w/index.php?title=Foam&action=edit&section=">adding to it</a>. <span class="date-container"><i>(<span class="date">August 2024</span>)</i></span></div></td></tr></tbody></table> <div class="mw-heading mw-heading3"><h3 id="Solid_foams">Solid foams</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=8" title="Edit section: Solid foams"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Solid foams, both open-cell and closed-cell, are considered as a sub-class of cellular structures. They often have lower nodal connectivity<sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Manual_of_Style#Technical_language" title="Wikipedia:Manual of Style"><span title="The material near this tag may be using jargon that limits the article's accessibility. (February 2024)">jargon</span></a></i>]</sup> as compared to other cellular structures like honeycombs and truss lattices, and thus, their failure mechanism is dominated by bending of members. Low nodal connectivity and the resulting failure mechanism ultimately lead to their lower mechanical strength and stiffness compared to honeycombs and truss lattices.<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> </p><p>The strength of foams can be impacted by the density, the material used, and the arrangement of the cellular structure (open vs closed and pore isotropy).<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2024)">citation needed</span></a></i>]</sup> To characterize the <a href="/wiki/Mechanical_properties" class="mw-redirect" title="Mechanical properties">mechanical properties</a> of foams, compressive <a href="/wiki/Stress%E2%80%93strain_curve" title="Stress–strain curve">stress-strain curves</a> are used to measure their strength and ability to absorb energy since this is an important factor in foam based technologies.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2024)">citation needed</span></a></i>]</sup> </p> <div class="mw-heading mw-heading4"><h4 id="Elastomeric_foam">Elastomeric foam</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=9" title="Edit section: Elastomeric foam"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>For <a href="/wiki/Elastomer" title="Elastomer">elastomeric</a> cellular solids, as the foam is compressed, first it behaves elastically as the cell walls bend, then as the cell walls buckle there is yielding and breakdown of the material until finally the cell walls crush together and the material ruptures.<sup id="cite_ref-:0_13-0" class="reference"><a href="#cite_note-:0-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> This is seen in a stress-strain curve as a steep linear elastic regime, a linear regime with a shallow slope after yielding (plateau stress), and an exponentially increasing regime. The stiffness of the material can be calculated from the linear elastic regime <sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> where the <a href="/wiki/Elastic_modulus" title="Elastic modulus">modulus</a> for open celled foams can be defined by the equation: </p> <figure typeof="mw:File/Thumb"><a href="/wiki/File:Compressive_Stress_Strain_Curve_of_Elastomeric_Foams.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/8/85/Compressive_Stress_Strain_Curve_of_Elastomeric_Foams.jpg/297px-Compressive_Stress_Strain_Curve_of_Elastomeric_Foams.jpg" decoding="async" width="297" height="236" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/8/85/Compressive_Stress_Strain_Curve_of_Elastomeric_Foams.jpg/446px-Compressive_Stress_Strain_Curve_of_Elastomeric_Foams.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/8/85/Compressive_Stress_Strain_Curve_of_Elastomeric_Foams.jpg/594px-Compressive_Stress_Strain_Curve_of_Elastomeric_Foams.jpg 2x" data-file-width="832" data-file-height="660" /></a><figcaption>Schematic stress-strain curve of an elastomeric foam, demonstrating the three regions which are linear elastic, cell-wall buckling, and cell-wall fracture, where the area under the curve specified represents the energy per unit volume the foam can absorb.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2024)">citation needed</span></a></i>]</sup></figcaption></figure> <p><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \left({\frac {E^{*}}{E_{s}}}\right)_{f}=C_{f}\left({\frac {\rho ^{*}}{\rho _{s}}}\right)^{2}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mrow> <mo>(</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <msup> <mi>E</mi> <mrow class="MJX-TeXAtom-ORD"> <mo>∗</mo> </mrow> </msup> <msub> <mi>E</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>s</mi> </mrow> </msub> </mfrac> </mrow> <mo>)</mo> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mi>f</mi> </mrow> </msub> <mo>=</mo> <msub> <mi>C</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>f</mi> </mrow> </msub> <msup> <mrow> <mo>(</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <msup> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mo>∗</mo> </mrow> </msup> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>s</mi> </mrow> </msub> </mfrac> </mrow> <mo>)</mo> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msup> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \left({\frac {E^{*}}{E_{s}}}\right)_{f}=C_{f}\left({\frac {\rho ^{*}}{\rho _{s}}}\right)^{2}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/8876c2aec461dfbd1bc92164b872da19a5d1a089" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.838ex; width:21.706ex; height:6.843ex;" alt="{\displaystyle \left({\frac {E^{*}}{E_{s}}}\right)_{f}=C_{f}\left({\frac {\rho ^{*}}{\rho _{s}}}\right)^{2}}" /></span> </p><p>where <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle E_{s}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>E</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>s</mi> </mrow> </msub> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle E_{s}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/b0c1623a2086aff18584e32b589d83c06ac4cdda" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:2.719ex; height:2.509ex;" alt="{\displaystyle E_{s}}" /></span> is the modulus of the solid component, <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle E^{*}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msup> <mi>E</mi> <mrow class="MJX-TeXAtom-ORD"> <mo>∗</mo> </mrow> </msup> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle E^{*}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/a91d2119445b3b65384ba491c4b95f1557571ecc" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:2.848ex; height:2.343ex;" alt="{\displaystyle E^{*}}" /></span> is the modulus of the honeycomb structure, <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle C_{f}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>C</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>f</mi> </mrow> </msub> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle C_{f}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/7765fc9102a19771111a01cd0b18c79e231029cf" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:2.798ex; height:2.843ex;" alt="{\displaystyle C_{f}}" /></span> is a constant having a value close to one, <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \rho ^{*}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msup> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mo>∗</mo> </mrow> </msup> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \rho ^{*}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/41b9afc5b13d9b11ab7cc83f865daa1f7fbee033" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:2.256ex; height:2.843ex;" alt="{\displaystyle \rho ^{*}}" /></span> is the density of the honeycomb structure, and <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \rho _{s}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>s</mi> </mrow> </msub> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \rho _{s}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/93e930969b2a38890057fd45843b5d18beb0bece" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:2.205ex; height:2.176ex;" alt="{\displaystyle \rho _{s}}" /></span> is the density of the solid. The elastic modulus for closed cell foams can be described similarly by: </p><p><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \left({\frac {E^{*}}{E_{s}}}\right)_{f}=C_{f}\left({\frac {\rho ^{*}}{\rho _{s}}}\right)^{3}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mrow> <mo>(</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <msup> <mi>E</mi> <mrow class="MJX-TeXAtom-ORD"> <mo>∗</mo> </mrow> </msup> <msub> <mi>E</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>s</mi> </mrow> </msub> </mfrac> </mrow> <mo>)</mo> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mi>f</mi> </mrow> </msub> <mo>=</mo> <msub> <mi>C</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>f</mi> </mrow> </msub> <msup> <mrow> <mo>(</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <msup> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mo>∗</mo> </mrow> </msup> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>s</mi> </mrow> </msub> </mfrac> </mrow> <mo>)</mo> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mn>3</mn> </mrow> </msup> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \left({\frac {E^{*}}{E_{s}}}\right)_{f}=C_{f}\left({\frac {\rho ^{*}}{\rho _{s}}}\right)^{3}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/ef1ed6562601159ca6decb3ceb73ad245fb7b85a" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.838ex; width:21.706ex; height:6.843ex;" alt="{\displaystyle \left({\frac {E^{*}}{E_{s}}}\right)_{f}=C_{f}\left({\frac {\rho ^{*}}{\rho _{s}}}\right)^{3}}" /></span> </p><p>where the only difference is the exponent in the density dependence. However, in real materials, a closed-cell foam has more material at the cell edges which makes it more closely follow the equation for open-cell foams.<sup id="cite_ref-15" class="reference"><a href="#cite_note-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> The ratio of the density of the honeycomb structure compared with the solid structure has a large impact on the modulus of the material. Overall, foam strength increases with density of the cell and stiffness of the matrix material. </p> <div class="mw-heading mw-heading4"><h4 id="Energy_of_deformation">Energy of deformation</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=10" title="Edit section: Energy of deformation"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Another important property which can be deduced from the stress strain curve is the energy that the foam is able to absorb. The area under the curve (specified to be before rapid densification at the peak stress), represents the energy in the foam in units of energy per unit volume. The maximum energy stored by the foam prior to rupture is described by the equation:<sup id="cite_ref-:0_13-1" class="reference"><a href="#cite_note-:0-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> </p><p><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\frac {W_{max}}{E_{s}}}=0.05\left({\frac {\rho ^{*}}{\rho _{s}}}\right)^{2}\left[0.975-1.4\left({\frac {\rho ^{*}}{\rho _{s}}}\right)\right]}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <msub> <mi>W</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>m</mi> <mi>a</mi> <mi>x</mi> </mrow> </msub> <msub> <mi>E</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>s</mi> </mrow> </msub> </mfrac> </mrow> <mo>=</mo> <mn>0.05</mn> <msup> <mrow> <mo>(</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <msup> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mo>∗</mo> </mrow> </msup> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>s</mi> </mrow> </msub> </mfrac> </mrow> <mo>)</mo> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msup> <mrow> <mo>[</mo> <mrow> <mn>0.975</mn> <mo>−</mo> <mn>1.4</mn> <mrow> <mo>(</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <msup> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mo>∗</mo> </mrow> </msup> <msub> <mi>ρ</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>s</mi> </mrow> </msub> </mfrac> </mrow> <mo>)</mo> </mrow> </mrow> <mo>]</mo> </mrow> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle {\frac {W_{max}}{E_{s}}}=0.05\left({\frac {\rho ^{*}}{\rho _{s}}}\right)^{2}\left[0.975-1.4\left({\frac {\rho ^{*}}{\rho _{s}}}\right)\right]}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/037551eb3a9f7c6a5595941b2b2336f792664d2f" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.505ex; width:42.167ex; height:6.509ex;" alt="{\displaystyle {\frac {W_{max}}{E_{s}}}=0.05\left({\frac {\rho ^{*}}{\rho _{s}}}\right)^{2}\left[0.975-1.4\left({\frac {\rho ^{*}}{\rho _{s}}}\right)\right]}" /></span> </p><p>This equation is derived from assuming an idealized foam with engineering approximations from experimental results. Most energy absorption occurs at the plateau stress region after the steep linear elastic regime.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2024)">citation needed</span></a></i>]</sup> </p> <div class="mw-heading mw-heading4"><h4 id="Directional_dependence">Directional dependence</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=11" title="Edit section: Directional dependence"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The <a href="/wiki/Isotropy" title="Isotropy">isotropy</a> of the cellular structure and the absorption of fluids can also have an impact on the mechanical properties of a foam. If there is anisotropy present, then the materials response to stress will be directionally dependent, and thus the stress-strain curve, modulus, and energy absorption will vary depending on the direction of applied force.<sup id="cite_ref-16" class="reference"><a href="#cite_note-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> Also, open-cell structures which have connected pores can allow water or other liquids to flow through the structure, which can also affect the rigidity and energy absorption capabilities.<sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Applications">Applications</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=12" title="Edit section: Applications"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Liquid_foams_2">Liquid foams</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=13" title="Edit section: Liquid foams"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Liquid foams can be used in <a href="/wiki/Fire_retardant_foam" class="mw-redirect" title="Fire retardant foam">fire retardant foam</a>, such as those that are used in extinguishing fires, especially <a href="/wiki/Oil_fire" class="mw-redirect" title="Oil fire">oil fires</a>.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2024)">citation needed</span></a></i>]</sup> </p><p>The dough of leavened <a href="/wiki/Bread" title="Bread">bread</a> has traditionally been understood as a closed-cell foam—<a href="/wiki/Yeast" title="Yeast">yeast</a> causing bread to rise via tiny bubbles of gas that become the bread <a href="/wiki/Pores_(bread)" class="mw-redirect" title="Pores (bread)">pores</a>—where the cells do not connect with each other. Cutting the dough releases the gas in the bubbles that are cut, but the gas in the rest of the dough cannot escape.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2024)">citation needed</span></a></i>]</sup> When dough is allowed to rise too far, it becomes an open-cell foam, in which the gas pockets are connected; cutting the dough surface at that point would cause a large volume of gas to escape, and the dough to collapse.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2024)">citation needed</span></a></i>]</sup><sup id="cite_ref-18" class="reference"><a href="#cite_note-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> Recent research has indicated that the pore structure in bread is 99% interconnected into one large vacuole, thus the closed-cell foam of the moist dough is transformed into an open cell solid foam in the bread.<sup id="cite_ref-19" class="reference"><a href="#cite_note-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup><sup class="noprint Inline-Template noprint Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:No_original_research#Primary,_secondary_and_tertiary_sources" title="Wikipedia:No original research"><span title="This claim needs references to reliable secondary sources. (August 2024)">non-primary source needed</span></a></i>]</sup> </p><p>The unique property of gas-liquid foams having very high specific surface area is exploited in the chemical processes of <a href="/wiki/Froth_flotation" title="Froth flotation">froth flotation</a> and <a href="/wiki/Foam_fractionation" title="Foam fractionation">foam fractionation</a>.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2024)">citation needed</span></a></i>]</sup> </p> <div class="mw-heading mw-heading4"><h4 id="Depopulation">Depopulation</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=14" title="Edit section: Depopulation"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><a href="/wiki/Foam_depopulation" title="Foam depopulation">Foam depopulation</a> or foaming is a means of mass killing farm animals by spraying foam over a large area to obstruct breathing and ultimately cause suffocation.<sup id="cite_ref-20" class="reference"><a href="#cite_note-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-21" class="reference"><a href="#cite_note-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup> It is usually used to attempt to stop disease spread.<sup id="cite_ref-22" class="reference"><a href="#cite_note-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Solid_foams_2">Solid foams</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=15" title="Edit section: Solid foams"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951" /><div role="note" class="hatnote navigation-not-searchable">Further information: <a href="/wiki/Polymeric_foam" title="Polymeric foam">Polymeric foam</a></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1251242444" /><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1248332772" /><table class="box-Multiple_issues plainlinks metadata ambox ambox-content ambox-multiple_issues compact-ambox" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/40px-Ambox_important.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/60px-Ambox_important.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/80px-Ambox_important.svg.png 2x" data-file-width="40" data-file-height="40" /></span></span></div></td><td class="mbox-text"><div class="mbox-text-span"><div class="multiple-issues-text mw-collapsible"><b>This section has multiple issues.</b> Please help <b><a href="/wiki/Special:EditPage/Foam" title="Special:EditPage/Foam">improve it</a></b> or discuss these issues on the <b><a href="/wiki/Talk:Foam" title="Talk:Foam">talk page</a></b>. <small><i>(<a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove these messages</a>)</i></small> <div class="mw-collapsible-content"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1251242444" /><table class="box-Original_research plainlinks metadata ambox ambox-content ambox-Original_research" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/40px-Ambox_important.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/60px-Ambox_important.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/80px-Ambox_important.svg.png 2x" data-file-width="40" data-file-height="40" /></span></span></div></td><td class="mbox-text"><div class="mbox-text-span">This section <b>possibly contains <a href="/wiki/Wikipedia:No_original_research" title="Wikipedia:No original research">original research</a></b>.<span class="hide-when-compact"> Please <a class="external text" href="https://en.wikipedia.org/w/index.php?title=Foam&action=edit">improve it</a> by <a href="/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">verifying</a> the claims made and adding <a href="/wiki/Wikipedia:Citing_sources#Inline_citations" title="Wikipedia:Citing sources">inline citations</a>. Statements consisting only of original research should be removed.</span> <span class="date-container"><i>(<span class="date">December 2020</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1251242444" /><table class="box-More_citations_needed plainlinks metadata ambox ambox-content ambox-Refimprove" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><a href="/wiki/File:Question_book-new.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png" decoding="async" width="50" height="39" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/75px-Question_book-new.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/100px-Question_book-new.svg.png 2x" data-file-width="512" data-file-height="399" /></a></span></div></td><td class="mbox-text"><div class="mbox-text-span">This section <b>needs additional citations for <a href="/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">verification</a></b>.<span class="hide-when-compact"> Please help <a href="/wiki/Special:EditPage/Foam" title="Special:EditPage/Foam">improve this article</a> by <a href="/wiki/Help:Referencing_for_beginners" title="Help:Referencing for beginners">adding citations to reliable sources</a> in this section. Unsourced material may be challenged and removed.<br /><small><span class="plainlinks"><i>Find sources:</i> <a rel="nofollow" class="external text" href="https://www.google.com/search?as_eq=wikipedia&q=%22Foam%22">"Foam"</a> – <a rel="nofollow" class="external text" href="https://www.google.com/search?tbm=nws&q=%22Foam%22+-wikipedia&tbs=ar:1">news</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?&q=%22Foam%22&tbs=bkt:s&tbm=bks">newspapers</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?tbs=bks:1&q=%22Foam%22+-wikipedia">books</a> <b>·</b> <a rel="nofollow" class="external text" href="https://scholar.google.com/scholar?q=%22Foam%22">scholar</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.jstor.org/action/doBasicSearch?Query=%22Foam%22&acc=on&wc=on">JSTOR</a></span></small></span> <span class="date-container"><i>(<span class="date">December 2020</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> </div> </div><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <p>Solid foams are a class of lightweight cellular engineering materials. These foams are typically classified into two types based on their pore structure: open-cell-structured foams (also known as <a href="/wiki/Reticulated_foam" title="Reticulated foam">reticulated foams</a>) and closed-cell foams. At high enough cell resolutions, any type can be treated as continuous or "continuum" materials and are referred to as <a href="/w/index.php?title=Cellular_solid&action=edit&redlink=1" class="new" title="Cellular solid (page does not exist)">cellular solids</a>,<sup id="cite_ref-Gibson_23-0" class="reference"><a href="#cite_note-Gibson-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> with predictable mechanical properties. </p> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Metal_Foam_in_Scanning_Electron_Microscope,_magnification_10x.GIF" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/a/af/Metal_Foam_in_Scanning_Electron_Microscope%2C_magnification_10x.GIF/250px-Metal_Foam_in_Scanning_Electron_Microscope%2C_magnification_10x.GIF" decoding="async" width="220" height="176" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/a/af/Metal_Foam_in_Scanning_Electron_Microscope%2C_magnification_10x.GIF/330px-Metal_Foam_in_Scanning_Electron_Microscope%2C_magnification_10x.GIF 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/a/af/Metal_Foam_in_Scanning_Electron_Microscope%2C_magnification_10x.GIF/500px-Metal_Foam_in_Scanning_Electron_Microscope%2C_magnification_10x.GIF 2x" data-file-width="1280" data-file-height="1024" /></a><figcaption>An open-cell metal foam</figcaption></figure> <p>Open-cell foams can be used to filter air. For example, a foam embedded with catalyst has been shown to catalytically convert <a href="/wiki/Formaldehyde" title="Formaldehyde">formaldehyde</a> to benign substances when formaldehyde polluted air passes through the open cell structure.<sup id="cite_ref-24" class="reference"><a href="#cite_note-24"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup> </p><p>Open-cell-structured foams contain pores that are connected to each other and form an interconnected network that is relatively soft. Open-cell foams fill with whatever gas surrounds them. If filled with air, a relatively good insulator results, but, if the open cells fill with water, insulation properties would be reduced. Recent studies have put the focus on studying the properties of open-cell foams as an insulator material. Wheat gluten/TEOS <a href="/wiki/Biofoams" class="mw-redirect" title="Biofoams">bio-foams</a> have been produced, showing similar insulator properties as for those foams obtained from oil-based resources.<sup id="cite_ref-25" class="reference"><a href="#cite_note-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> Foam rubber is a type of open-cell foam. </p> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Closed_cell_metal_foam_with_large_cell_size.JPG" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/9/9e/Closed_cell_metal_foam_with_large_cell_size.JPG/220px-Closed_cell_metal_foam_with_large_cell_size.JPG" decoding="async" width="220" height="184" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/9/9e/Closed_cell_metal_foam_with_large_cell_size.JPG/330px-Closed_cell_metal_foam_with_large_cell_size.JPG 1.5x, //upload.wikimedia.org/wikipedia/commons/9/9e/Closed_cell_metal_foam_with_large_cell_size.JPG 2x" data-file-width="414" data-file-height="347" /></a><figcaption>A closed-cell metal foam</figcaption></figure> <p>Closed-cell foams do not have interconnected pores. The closed-cell foams normally have higher compressive strength due to their structures. However, closed-cell foams are also, in general more dense, require more material, and as a consequence are more expensive to produce. The closed cells can be filled with a specialized gas to provide improved insulation. The closed-cell structure foams have higher dimensional stability, low moisture absorption coefficients, and higher strength compared to open-cell-structured foams. All types of foam are widely used as core material in <a href="/wiki/Sandwich-structured_composite" title="Sandwich-structured composite">sandwich-structured composite</a> materials. </p><p>The earliest known engineering use of cellular solids is with wood, which in its dry form is a closed-cell foam composed of lignin, cellulose, and air. From the early 20th century, various types of specially manufactured solid foams came into use. The low <a href="/wiki/Density" title="Density">density</a> of these foams makes them excellent as thermal <a href="/wiki/Thermal_insulation" title="Thermal insulation">insulators</a> and flotation devices and their lightness and compressibility make them ideal as packing materials and stuffings. </p><p>An example of the use of azodicarbonamide<sup id="cite_ref-26" class="reference"><a href="#cite_note-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> as a <a href="/wiki/Blowing_agent" title="Blowing agent">blowing agent</a> is found in the manufacture of <a href="/wiki/Polyvinyl_chloride" title="Polyvinyl chloride">vinyl (PVC)</a> and <a href="/wiki/Ethylene-vinyl_acetate" title="Ethylene-vinyl acetate">EVA-PE foams</a>, where it plays a role in the formation of air bubbles by breaking down into gas at high temperature.<sup id="cite_ref-27" class="reference"><a href="#cite_note-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-28" class="reference"><a href="#cite_note-28"><span class="cite-bracket">[</span>28<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-29" class="reference"><a href="#cite_note-29"><span class="cite-bracket">[</span>29<span class="cite-bracket">]</span></a></sup> </p><p>The random or "stochastic" geometry of these foams makes them good for energy absorption, as well. In the late 20th century to early 21st century, new manufacturing techniques have allowed for geometry that results in excellent strength and stiffness per weight. These new materials are typically referred to as engineered cellular solids.<sup id="cite_ref-Gibson_23-1" class="reference"><a href="#cite_note-Gibson-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading4"><h4 id="Syntactic_foam">Syntactic foam</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=16" title="Edit section: Syntactic foam"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951" /><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Syntactic_foam" title="Syntactic foam">Syntactic foam</a></div> <div class="mw-heading mw-heading4"><h4 id="Integral_skin_foam">Integral skin foam</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=17" title="Edit section: Integral skin foam"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><i>Integral skin foam</i>, also known as <i>self-skin foam</i>, is a type of foam with a high-density skin and a low-density core. It can be formed in an <i>open-mold process</i> or a <i>closed-mold process</i>. In the open-mold process, two reactive components are mixed and poured into an open mold. The mold is then closed and the mixture is allowed to expand and cure. Examples of items produced using this process include <a href="/wiki/Arm_rest" class="mw-redirect" title="Arm rest">arm rests</a>, <a href="/wiki/Baby_seat" class="mw-redirect" title="Baby seat">baby seats</a>, <a href="/wiki/Shoe_sole" class="mw-redirect" title="Shoe sole">shoe soles</a>, and <a href="/wiki/Mattress" title="Mattress">mattresses</a>. The closed-mold process, more commonly known as <i><a href="/wiki/Reaction_injection_molding" title="Reaction injection molding">reaction injection molding</a></i> (RIM), injects the mixed components into a closed mold under high pressures.<sup id="cite_ref-30" class="reference"><a href="#cite_note-30"><span class="cite-bracket">[</span>30<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Gallery">Gallery</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=18" title="Edit section: Gallery"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul class="gallery mw-gallery-traditional"> <li class="gallerybox" style="width: 155px"> <div class="thumb" style="width: 150px; height: 150px;"><span typeof="mw:File"><a href="/wiki/File:FoamedPlastic.jpg" class="mw-file-description" title="Micrograph of temper (memory) foam"><img alt="Micrograph of temper (memory) foam" src="//upload.wikimedia.org/wikipedia/commons/thumb/5/55/FoamedPlastic.jpg/120px-FoamedPlastic.jpg" decoding="async" width="120" height="90" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/55/FoamedPlastic.jpg/250px-FoamedPlastic.jpg 1.5x" data-file-width="4024" data-file-height="3016" /></a></span></div> <div class="gallerytext"><a href="/wiki/Micrograph" title="Micrograph">Micrograph</a> of <a href="/wiki/Temper_foam" class="mw-redirect" title="Temper foam">temper</a> (memory) foam</div> </li> <li class="gallerybox" style="width: 155px"> <div class="thumb" style="width: 150px; height: 150px;"><span typeof="mw:File"><a href="/wiki/File:Silikonschaum_riesenblase_verfuellungsversuch.jpg" class="mw-file-description" title="Silicone foam penetration seal [clarification needed]"><img alt="Silicone foam penetration seal [clarification needed]" src="//upload.wikimedia.org/wikipedia/commons/thumb/f/f6/Silikonschaum_riesenblase_verfuellungsversuch.jpg/120px-Silikonschaum_riesenblase_verfuellungsversuch.jpg" decoding="async" width="120" height="78" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/f6/Silikonschaum_riesenblase_verfuellungsversuch.jpg/250px-Silikonschaum_riesenblase_verfuellungsversuch.jpg 1.5x" data-file-width="5184" data-file-height="3360" /></a></span></div> <div class="gallerytext"><a href="/wiki/Silicone_foam" title="Silicone foam">Silicone foam</a> <a href="/wiki/Firestop" title="Firestop">penetration seal</a> <sup class="noprint Inline-Template" style="margin-left:0.1em; white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Please_clarify" title="Wikipedia:Please clarify"><span title="The text near this tag may need clarification or removal of jargon. (August 2024)">clarification needed</span></a></i>]</sup></div> </li> <li class="gallerybox" style="width: 155px"> <div class="thumb" style="width: 150px; height: 150px;"><span typeof="mw:File"><a href="/wiki/File:Foam_ball.png" class="mw-file-description" title="Industrial CT scanning of a foam ball [clarification needed]"><img alt="Industrial CT scanning of a foam ball [clarification needed]" src="//upload.wikimedia.org/wikipedia/commons/thumb/9/9d/Foam_ball.png/120px-Foam_ball.png" decoding="async" width="120" height="110" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/9/9d/Foam_ball.png/180px-Foam_ball.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/9/9d/Foam_ball.png/240px-Foam_ball.png 2x" data-file-width="1101" data-file-height="1011" /></a></span></div> <div class="gallerytext"><a href="/wiki/Industrial_CT_scanning" class="mw-redirect" title="Industrial CT scanning">Industrial CT scanning</a> of a foam ball <sup class="noprint Inline-Template" style="margin-left:0.1em; white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Please_clarify" title="Wikipedia:Please clarify"><span title="The text near this tag may need clarification or removal of jargon. (August 2024)">clarification needed</span></a></i>]</sup></div> </li> <li class="gallerybox" style="width: 155px"> <div class="thumb" style="width: 150px; height: 150px;"><span typeof="mw:File"><a href="/wiki/File:Expanded_polystyrene_foam_dunnage.jpg" class="mw-file-description" title="Polystyrene foam cushioning"><img alt="Polystyrene foam cushioning" src="//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Expanded_polystyrene_foam_dunnage.jpg/120px-Expanded_polystyrene_foam_dunnage.jpg" decoding="async" width="120" height="108" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Expanded_polystyrene_foam_dunnage.jpg/250px-Expanded_polystyrene_foam_dunnage.jpg 1.5x" data-file-width="1303" data-file-height="1176" /></a></span></div> <div class="gallerytext">Polystyrene foam <a href="/wiki/Cushioning" class="mw-redirect" title="Cushioning">cushioning</a></div> </li> <li class="gallerybox" style="width: 155px"> <div class="thumb" style="width: 150px; height: 150px;"><span typeof="mw:File"><a href="/wiki/File:Aluminium_foam.jpg" class="mw-file-description" title="Foamed aluminum [clarification needed]"><img alt="Foamed aluminum [clarification needed]" src="//upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Aluminium_foam.jpg/90px-Aluminium_foam.jpg" decoding="async" width="90" height="120" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Aluminium_foam.jpg/135px-Aluminium_foam.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Aluminium_foam.jpg/180px-Aluminium_foam.jpg 2x" data-file-width="1635" data-file-height="2180" /></a></span></div> <div class="gallerytext"><a href="/wiki/Metal_foam" title="Metal foam">Foamed</a> <a href="/wiki/Aluminum" class="mw-redirect" title="Aluminum">aluminum</a> <sup class="noprint Inline-Template" style="margin-left:0.1em; white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Please_clarify" title="Wikipedia:Please clarify"><span title="The text near this tag may need clarification or removal of jargon. (August 2024)">clarification needed</span></a></i>]</sup></div> </li> </ul> <div class="mw-heading mw-heading2"><h2 id="Foam_scales_and_properties">Foam scales and properties</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=19" title="Edit section: Foam scales and properties"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol 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a>span,.mw-parser-output .navbar a>abbr{text-decoration:inherit}.mw-parser-output .navbar-mini abbr{font-variant:small-caps;border-bottom:none;text-decoration:none;cursor:inherit}.mw-parser-output .navbar-ct-full{font-size:114%;margin:0 7em}.mw-parser-output .navbar-ct-mini{font-size:114%;margin:0 4em}html.skin-theme-clientpref-night .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}@media(prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}}@media print{.mw-parser-output .navbar{display:none!important}}</style><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Foam_scales_and_properties" title="Template:Foam scales and properties"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Foam_scales_and_properties" title="Template talk:Foam scales and properties"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Foam_scales_and_properties" title="Special:EditPage/Template:Foam scales and properties"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Foam_scales_and_properties26" style="font-size:114%;margin:0 4em">Foam scales and properties</div></th></tr><tr><td colspan="2" class="navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0px"> <table class="wikitable" style="margin: 0"> <tbody><tr> <th>Scale </th> <th>Generation </th> <th>Structure </th> <th>Stability </th> <th>Dynamic </th> <th>Experiments and characterization </th> <th>Transport properties </th> <th>Irisations </th> <th>Maths </th> <th>Applications </th> <th>Fun </th></tr> <tr> <td><a href="/wiki/Surfactant" title="Surfactant">Surfactants</a></td> <td></td> <td><a href="/wiki/Micelle" title="Micelle">Micelles</a>, <a href="/wiki/Hydrophilic-lipophilic_balance" title="Hydrophilic-lipophilic balance">HLB</a></td> <td></td> <td><a href="/wiki/Surface_rheology" title="Surface rheology">Surface rheology</a>, <a href="/wiki/Adsorption" title="Adsorption">adsorption</a></td> <td><a href="/wiki/Langmuir%E2%80%93Blodgett_trough" title="Langmuir–Blodgett trough">Langmuir trough</a>, <a href="/wiki/Ellipsometry" title="Ellipsometry">ellipsometry</a>, <a href="/wiki/X-ray_scattering_techniques" title="X-ray scattering techniques">Xray</a>, <a href="/wiki/Surface_rheology" title="Surface rheology">surface rheology</a></td> <td></td> <td></td> <td></td> <td></td> <td> </td></tr> <tr> <td><a href="/wiki/Soap_film" title="Soap film">Films</a></td> <td>Frankel's law</td> <td><a href="/wiki/Surface_tension" title="Surface tension">Surface tension</a>, <a href="/wiki/DLVO_theory" title="DLVO theory">DLVO</a>, <a href="/wiki/Disjoining_pressure" title="Disjoining pressure">disjoining pressure</a></td> <td><a href="/wiki/Dewetting" title="Dewetting">dewetting</a>, bursting</td> <td><a href="/wiki/Marangoni_effect" title="Marangoni effect">Marangoni</a>, <a href="/wiki/Surface_rheology" title="Surface rheology">surface rheology</a></td> <td><a href="/wiki/Interferometry" title="Interferometry">Interferometry</a>, <a href="/wiki/Langmuir%E2%80%93Blodgett_trough" title="Langmuir–Blodgett trough">Thin film balance</a></td> <td></td> <td><a href="/wiki/Interference_(wave_propagation)" class="mw-redirect" title="Interference (wave propagation)">Interferences</a></td> <td><a href="/wiki/Double_bubble_theorem" title="Double bubble theorem">double bubble theorem</a></td> <td></td> <td>Giant films </td></tr> <tr> <td><a href="/wiki/Soap_bubble" title="Soap bubble">Bubbles</a></td> <td></td> <td>shape, <a href="/wiki/Plateau%27s_laws" title="Plateau's laws">Plateau's laws</a></td> <td>foam <a href="/wiki/Drainage" title="Drainage">drainage</a></td> <td><a href="/wiki/T1_process" title="T1 process">T1 process</a></td> <td></td> <td><a href="/wiki/Acoustics" title="Acoustics">acoustics</a>, <a href="/wiki/Conductivity_(electrolytic)" title="Conductivity (electrolytic)">electric</a></td> <td><a href="/wiki/Interference_(wave_propagation)" class="mw-redirect" title="Interference (wave propagation)">Interferences</a></td> <td>double bubble theory</td> <td></td> <td>Giant bubbles, coloured bubbles, freezing </td></tr> <tr> <td><a class="mw-selflink selflink">Foam</a></td> <td></td> <td><a href="/wiki/Volume_fraction" title="Volume fraction">Liquid fraction</a>, <a href="/wiki/Metastability" title="Metastability">metastable</a> state</td> <td><a href="/wiki/Coalescence_(physics)" title="Coalescence (physics)">Coalescence</a>, avalanches, <a href="/wiki/Ostwald_ripening" title="Ostwald ripening">coarsening</a>, foam <a href="/wiki/Drainage" title="Drainage">drainage</a></td> <td><a href="/wiki/Rheology" title="Rheology">rheology</a></td> <td><a href="/wiki/Light_scattering" class="mw-redirect" title="Light scattering">light scattering</a> <a href="/wiki/Acoustics" title="Acoustics">acoustics</a>, <a href="/wiki/Electrical_conductivity_meter" title="Electrical conductivity meter">conductimetry</a>, <a href="/wiki/Surface_Evolver" title="Surface Evolver">Surface Evolver</a>, bubble model, <a href="/wiki/Potts_model" title="Potts model">Potts' model</a></td> <td><a href="/wiki/Acoustics" title="Acoustics">acoustics</a>, <a href="/wiki/Light_scattering" class="mw-redirect" title="Light scattering">light scattering</a></td> <td><a href="/wiki/Light_scattering" class="mw-redirect" title="Light scattering">light scattering</a></td> <td><a href="/wiki/Packing_problem" class="mw-redirect" title="Packing problem">Packing</a> and <a href="/wiki/Topology" title="Topology">topology</a></td> <td>Aquafoams</td> <td> </td></tr></tbody></table> </div></td></tr></tbody></table></div> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=20" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Aluminium_foam_sandwich" title="Aluminium foam sandwich">Aluminium foam sandwich</a></li> <li><a href="/wiki/Ballistic_foam" title="Ballistic foam">Ballistic foam</a></li> <li><a href="/wiki/Chaotic_bubble" title="Chaotic bubble">Chaotic bubble</a></li> <li><a href="/wiki/Defoamer" title="Defoamer">Defoamer</a></li> <li><a href="/wiki/Foam_glass" title="Foam glass">Foam glass</a></li> <li><a href="/wiki/Metal_foam" title="Metal foam">Metal foam</a></li> <li><a href="/wiki/Nanofoam" title="Nanofoam">Nanofoam</a></li> <li><a href="/wiki/Sea_foam" title="Sea foam">Sea foam</a></li> <li><a href="/wiki/Reversibly_assembled_cellular_composite_materials" title="Reversibly assembled cellular composite materials">Reversibly assembled cellular composite materials</a></li> <li><a href="/wiki/Foam_party" title="Foam party">Foam party</a></li> <li><a href="/wiki/Soft_matter" title="Soft matter">Soft matter</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=21" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist reflist-columns references-column-width" style="column-width: 30em;"> <ol class="references"> <li id="cite_note-WeaireHutzler1999-1"><span class="mw-cite-backlink">^ <a href="#cite_ref-WeaireHutzler1999_1-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-WeaireHutzler1999_1-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-WeaireHutzler1999_1-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-WeaireHutzler1999_1-3"><sup><i><b>d</b></i></sup></a> <a href="#cite_ref-WeaireHutzler1999_1-4"><sup><i><b>e</b></i></sup></a></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFWeaireHutzler1999" class="citation book cs1">Weaire, D.L.; Hutzler, Stefan (1999). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=mEHlZ9ZodFsC"><i>The Physics of Foams</i></a>. Oxford, England: Oxford University Press. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0198510977" title="Special:BookSources/0198510977"><bdi>0198510977</bdi></a><span class="reference-accessdate">. Retrieved <span class="nowrap">August 30,</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Physics+of+Foams&rft.place=Oxford%2C+England&rft.pub=Oxford+University+Press&rft.date=1999&rft.isbn=0198510977&rft.aulast=Weaire&rft.aufirst=D.L.&rft.au=Hutzler%2C+Stefan&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DmEHlZ9ZodFsC&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span> Note, this source focuses only on liquid foams.</span> </li> <li id="cite_note-Cantat_etal_1999-2"><span class="mw-cite-backlink">^ <a href="#cite_ref-Cantat_etal_1999_2-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Cantat_etal_1999_2-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFCantat,_I;_Cohen-Addad,_S;_Elias,_F;_Graner,_F;_Höhler,_R;_Pitois,_O;_Rouyer,_F_&_Saint-Jalmes,_A2013" class="citation book cs1"><a href="/wiki/Isabelle_Cantat" title="Isabelle Cantat">Cantat, I</a>; Cohen-Addad, S; Elias, F; Graner, F; Höhler, R; Pitois, O; Rouyer, F & Saint-Jalmes, A (2013). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=Ndzzl1hUNRoC"><i>Foams: Structure and Dynamics</i></a>. Oxford, England: Oxford University Press. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0199662890" title="Special:BookSources/978-0199662890"><bdi>978-0199662890</bdi></a><span class="reference-accessdate">. Retrieved <span class="nowrap">August 30,</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Foams%3A+Structure+and+Dynamics&rft.place=Oxford%2C+England&rft.pub=Oxford+University+Press&rft.date=2013&rft.isbn=978-0199662890&rft.au=Cantat%2C+I%3B+Cohen-Addad%2C+S%3B+Elias%2C+F%3B+Graner%2C+F%3B+H%C3%B6hler%2C+R%3B+Pitois%2C+O%3B+Rouyer%2C+F+%26+Saint-Jalmes%2C+A&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DNdzzl1hUNRoC&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span><span class="cs1-maint citation-comment"><code class="cs1-code">{{<a href="/wiki/Template:Cite_book" title="Template:Cite book">cite book</a>}}</code>: CS1 maint: multiple names: authors list (<a href="/wiki/Category:CS1_maint:_multiple_names:_authors_list" title="Category:CS1 maint: multiple names: authors list">link</a>)</span> Note, this source also focuses on liquid foams.</span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text">The general use of the term, which includes both noun and verb forms, is both narrower and broader than the one from material science described here. In general use, it is narrower, in that it most often refers to liquid foams; it is broader in that it includes all manners of such, and the actions to produce them, hence, according to <a href="/wiki/Merriam-Webster" title="Merriam-Webster">Merriam-Webster</a>, the term refers to "a light frothy mass of fine bubbles formed in or on the surface of a liquid or from a liquid", giving the examples of those produced by "salivating or sweating", ones stably produced to fight fires, ones that are the product of gas bubbles introduced during manufacturing, and then the further broad examples of sea foam, and then anything resembling the foregoing. Finally, the general definition includes actions to produce all of the above. See <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.merriam-webster.com/dictionary/foam">"Foam"</a>. <i>Merriam-Webster</i>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20141209213221/http://www.merriam-webster.com/dictionary/foam">Archived</a> from the original on December 9, 2014.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Merriam-Webster&rft.atitle=Foam&rft_id=http%3A%2F%2Fwww.merriam-webster.com%2Fdictionary%2Ffoam&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFIUPAC1997" class="citation book cs1">IUPAC (1997). <a rel="nofollow" class="external text" href="http://goldbook.iupac.org/E02065.html">"Emulsion"</a>. <i>Compendium of Chemical Terminology (The "Gold Book")</i>. Oxford: <a href="/wiki/Blackwell_Scientific_Publications" class="mw-redirect" title="Blackwell Scientific Publications">Blackwell Scientific Publications</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1351%2Fgoldbook.E02065">10.1351/goldbook.E02065</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-9678550-9-7" title="Special:BookSources/978-0-9678550-9-7"><bdi>978-0-9678550-9-7</bdi></a>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20120310221658/http://goldbook.iupac.org/E02065.html">Archived</a> from the original on March 10, 2012.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Emulsion&rft.btitle=Compendium+of+Chemical+Terminology+%28The+%22Gold+Book%22%29&rft.place=Oxford&rft.pub=Blackwell+Scientific+Publications&rft.date=1997&rft_id=info%3Adoi%2F10.1351%2Fgoldbook.E02065&rft.isbn=978-0-9678550-9-7&rft.au=IUPAC&rft_id=http%3A%2F%2Fgoldbook.iupac.org%2FE02065.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFLucassen1981" class="citation book cs1">Lucassen, J. (1981). Lucassen-Reijnders, E. H. (ed.). <i>Anionic Surfactants – Physical Chemistry of Surfactant Action</i>. NY, USA: Marcel Dekker.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Anionic+Surfactants+%E2%80%93+Physical+Chemistry+of+Surfactant+Action&rft.place=NY%2C+USA&rft.pub=Marcel+Dekker&rft.date=1981&rft.aulast=Lucassen&rft.aufirst=J.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span><sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citing_sources" title="Wikipedia:Citing sources"><span title="This citation requires a reference to the specific page or range of pages in which the material appears. (August 2024)">page needed</span></a></i>]</sup></span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFMorgan2008" class="citation journal cs1">Morgan, F. (2008). "Existence of Least-perimeter Partitions". <i>Philosophical Magazine Letters</i>. <b>88</b> (<span class="nowrap">9–</span>10): <span class="nowrap">647–</span>650. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://arxiv.org/abs/0711.4228">0711.4228</a></span>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2008PMagL..88..647M">2008PMagL..88..647M</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1080%2F09500830801992849">10.1080/09500830801992849</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Philosophical+Magazine+Letters&rft.atitle=Existence+of+Least-perimeter+Partitions&rft.volume=88&rft.issue=%3Cspan+class%3D%22nowrap%22%3E9%E2%80%93%3C%2Fspan%3E10&rft.pages=%3Cspan+class%3D%22nowrap%22%3E647-%3C%2Fspan%3E650&rft.date=2008&rft_id=info%3Aarxiv%2F0711.4228&rft_id=info%3Adoi%2F10.1080%2F09500830801992849&rft_id=info%3Abibcode%2F2008PMagL..88..647M&rft.aulast=Morgan&rft.aufirst=F.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-autogenerated1-7"><span class="mw-cite-backlink">^ <a href="#cite_ref-autogenerated1_7-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-autogenerated1_7-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">Bikerman, J.J. "Formation and Structure" in <i>Foams</i> New York, Springer-Verlag, 1973. ch 2. sec 24–25</span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20131212090241/http://www.clariant.com/C12575E4001FB2B8/vwLookupDownloads/2009_01_IHC_Newsletter_Defoaming.pdf/$FILE/2009_01_IHC_Newsletter_Defoaming.pdf">"The Foam"</a> <span class="cs1-format">(PDF)</span>. <i>IHC News</i>. January 2009. Archived from <a rel="nofollow" class="external text" href="http://www.clariant.com/C12575E4001FB2B8/vwLookupDownloads/2009_01_IHC_Newsletter_Defoaming.pdf/$FILE/2009_01_IHC_Newsletter_Defoaming.pdf">the original</a> <span class="cs1-format">(PDF)</span> on December 12, 2013<span class="reference-accessdate">. Retrieved <span class="nowrap">December 9,</span> 2013</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=IHC+News&rft.atitle=The+Foam&rft.date=2009-01&rft_id=http%3A%2F%2Fwww.clariant.com%2FC12575E4001FB2B8%2FvwLookupDownloads%2F2009_01_IHC_Newsletter_Defoaming.pdf%2F%24FILE%2F2009_01_IHC_Newsletter_Defoaming.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFStevenson2012" class="citation book cs1">Stevenson, Paul (January 3, 2012). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=FXAM3eBpZ0kC&dq=info:LfvRsPG2-6QJ:scholar.google.com/&pg=PT10"><i>Foam Engineering: Fundamentals and Applications</i></a>. John Wiley & Sons. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9781119961093" title="Special:BookSources/9781119961093"><bdi>9781119961093</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Foam+Engineering%3A+Fundamentals+and+Applications&rft.pub=John+Wiley+%26+Sons&rft.date=2012-01-03&rft.isbn=9781119961093&rft.aulast=Stevenson&rft.aufirst=Paul&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DFXAM3eBpZ0kC%26dq%3Dinfo%3ALfvRsPG2-6QJ%3Ascholar.google.com%2F%26pg%3DPT10&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text">Wilson, A.J, "Principles of Foam Formation and Stability." <i>Foams: Physics, Chemistry, and Structure</i>. New York, Springer-Verlag, 1989, ch 1</span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFQueheillaltWadley2005" class="citation journal cs1">Queheillalt, Douglas T.; Wadley, Haydn N.G. (January 2005). "Cellular metal lattices with hollow trusses". <i>Acta Materialia</i>. <b>53</b> (2): <span class="nowrap">303–</span>313. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2005AcMat..53..303Q">2005AcMat..53..303Q</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.actamat.2004.09.024">10.1016/j.actamat.2004.09.024</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Acta+Materialia&rft.atitle=Cellular+metal+lattices+with+hollow+trusses&rft.volume=53&rft.issue=2&rft.pages=%3Cspan+class%3D%22nowrap%22%3E303-%3C%2Fspan%3E313&rft.date=2005-01&rft_id=info%3Adoi%2F10.1016%2Fj.actamat.2004.09.024&rft_id=info%3Abibcode%2F2005AcMat..53..303Q&rft.aulast=Queheillalt&rft.aufirst=Douglas+T.&rft.au=Wadley%2C+Haydn+N.G.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFKooistraDeshpandeWadley2004" class="citation journal cs1">Kooistra, Gregory W.; Deshpande, Vikram S.; Wadley, Haydn N.G. (August 2004). "Compressive behavior of age hardenable tetrahedral lattice truss structures made from aluminium". <i>Acta Materialia</i>. <b>52</b> (14): <span class="nowrap">4229–</span>4237. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2004AcMat..52.4229K">2004AcMat..52.4229K</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.actamat.2004.05.039">10.1016/j.actamat.2004.05.039</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:13958881">13958881</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Acta+Materialia&rft.atitle=Compressive+behavior+of+age+hardenable+tetrahedral+lattice+truss+structures+made+from+aluminium&rft.volume=52&rft.issue=14&rft.pages=%3Cspan+class%3D%22nowrap%22%3E4229-%3C%2Fspan%3E4237&rft.date=2004-08&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A13958881%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1016%2Fj.actamat.2004.05.039&rft_id=info%3Abibcode%2F2004AcMat..52.4229K&rft.aulast=Kooistra&rft.aufirst=Gregory+W.&rft.au=Deshpande%2C+Vikram+S.&rft.au=Wadley%2C+Haydn+N.G.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-:0-13"><span class="mw-cite-backlink">^ <a href="#cite_ref-:0_13-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-:0_13-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFCourtney2005" class="citation book cs1">Courtney, Thomas H. (2005). <i>Mechanical Behavior of Materials</i>. Waveland Press, Inc. pp. <span class="nowrap">686–</span>713. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/1-57766-425-6" title="Special:BookSources/1-57766-425-6"><bdi>1-57766-425-6</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Mechanical+Behavior+of+Materials&rft.pages=%3Cspan+class%3D%22nowrap%22%3E686-%3C%2Fspan%3E713&rft.pub=Waveland+Press%2C+Inc&rft.date=2005&rft.isbn=1-57766-425-6&rft.aulast=Courtney&rft.aufirst=Thomas+H.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text"> <a rel="nofollow" class="external text" href="https://hal.science/hal-02344039">M. Liu et al. Multiscale modeling of effective elastic properties of fluid-filled porous materials</a> International Journal of Solids and Structures (2019) 162, 36-44 </span> </li> <li id="cite_note-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-15">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFAshby1983" class="citation journal cs1">Ashby, M. F. (1983). <a rel="nofollow" class="external text" href="https://doi.org/10.1007/bf02645546">"The Mechanical Properties of Cellular Solids"</a>. <i>Metallurgical Transactions</i>. <b>14A</b> (9): <span class="nowrap">1755–</span>1769. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1983MTA....14.1755A">1983MTA....14.1755A</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1007%2Fbf02645546">10.1007/bf02645546</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:135765088">135765088</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Metallurgical+Transactions&rft.atitle=The+Mechanical+Properties+of+Cellular+Solids&rft.volume=14A&rft.issue=9&rft.pages=%3Cspan+class%3D%22nowrap%22%3E1755-%3C%2Fspan%3E1769&rft.date=1983&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A135765088%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1007%2Fbf02645546&rft_id=info%3Abibcode%2F1983MTA....14.1755A&rft.aulast=Ashby&rft.aufirst=M.+F.&rft_id=https%3A%2F%2Fdoi.org%2F10.1007%2Fbf02645546&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-16"><span class="mw-cite-backlink"><b><a href="#cite_ref-16">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFLiGuoShim2020" class="citation journal cs1">Li, Pei; Guo, Y. B.; Shim, V. P. W. (2020). <a rel="nofollow" class="external text" href="https://doi.org/10.1016/j.ijsolstr.2020.08.007">"A rate-sensitive constitutive model for anisotropic cellular materials - Application to a transversely isotropic polyurethane foam"</a>. <i>International Journal of Solids and Structures</i>. <b>206</b>: <span class="nowrap">43–</span>58. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.ijsolstr.2020.08.007">10.1016/j.ijsolstr.2020.08.007</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:225310568">225310568</a> – via Elsevier.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=International+Journal+of+Solids+and+Structures&rft.atitle=A+rate-sensitive+constitutive+model+for+anisotropic+cellular+materials+-+Application+to+a+transversely+isotropic+polyurethane+foam&rft.volume=206&rft.pages=%3Cspan+class%3D%22nowrap%22%3E43-%3C%2Fspan%3E58&rft.date=2020&rft_id=info%3Adoi%2F10.1016%2Fj.ijsolstr.2020.08.007&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A225310568%23id-name%3DS2CID&rft.aulast=Li&rft.aufirst=Pei&rft.au=Guo%2C+Y.+B.&rft.au=Shim%2C+V.+P.+W.&rft_id=https%3A%2F%2Fdoi.org%2F10.1016%2Fj.ijsolstr.2020.08.007&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-17">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFYuHearonWilsonMaitland2011" class="citation journal cs1">Yu, Y. J.; Hearon, K.; Wilson, T. S.; Maitland, D. J. (2011). <a rel="nofollow" class="external text" href="https://dx.doi.org/10.1088/0964-1726/20/8/085010">"The effect of moisture absorption on thephysical properties of polyurethane shapememory polymer foams"</a>. <i>Smart Materials and Structures</i>. <b>20</b> (8). <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2011SMaS...20h5010Y">2011SMaS...20h5010Y</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1088%2F0964-1726%2F20%2F8%2F085010">10.1088/0964-1726/20/8/085010</a>. <a href="/wiki/PMC_(identifier)" class="mw-redirect" title="PMC (identifier)">PMC</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3176498">3176498</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/21949469">21949469</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Smart+Materials+and+Structures&rft.atitle=The+effect+of+moisture+absorption+on+thephysical+properties+of+polyurethane+shapememory+polymer+foams&rft.volume=20&rft.issue=8&rft.date=2011&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC3176498%23id-name%3DPMC&rft_id=info%3Apmid%2F21949469&rft_id=info%3Adoi%2F10.1088%2F0964-1726%2F20%2F8%2F085010&rft_id=info%3Abibcode%2F2011SMaS...20h5010Y&rft.aulast=Yu&rft.aufirst=Y.+J.&rft.au=Hearon%2C+K.&rft.au=Wilson%2C+T.+S.&rft.au=Maitland%2C+D.+J.&rft_id=http%3A%2F%2Fdx.doi.org%2F10.1088%2F0964-1726%2F20%2F8%2F085010&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-18">^</a></b></span> <span class="reference-text">The open structure of an over-risen dough is easy to observe: instead of consisting of discrete gas bubbles, the dough consists of a gas space filled with threads of the flour-water paste.<sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:No_original_research" title="Wikipedia:No original research"><span title="The material near this tag possibly contains original research. (August 2024)">original research?</span></a></i>]</sup><sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2024)">citation needed</span></a></i>]</sup></span> </li> <li id="cite_note-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-19">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFWangAustinChakrabati-Bell2011" class="citation journal cs1">Wang, Shuo; Austin, Peter; Chakrabati-Bell, Sumana (2011). "It's a maze: The pore structure of bread crumbs". <i>Journal of Cereal Science</i>. <b>54</b> (2): <span class="nowrap">203–</span>210. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.jcs.2011.05.004">10.1016/j.jcs.2011.05.004</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Journal+of+Cereal+Science&rft.atitle=It%27s+a+maze%3A+The+pore+structure+of+bread+crumbs&rft.volume=54&rft.issue=2&rft.pages=%3Cspan+class%3D%22nowrap%22%3E203-%3C%2Fspan%3E210&rft.date=2011&rft_id=info%3Adoi%2F10.1016%2Fj.jcs.2011.05.004&rft.aulast=Wang&rft.aufirst=Shuo&rft.au=Austin%2C+Peter&rft.au=Chakrabati-Bell%2C+Sumana&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-20"><span class="mw-cite-backlink"><b><a href="#cite_ref-20">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.nbcnews.com/id/wbna19036479">"New weapon in war on bird flu: tiny bubbles"</a>. <i>NBC News</i>. June 10, 2007<span class="reference-accessdate">. Retrieved <span class="nowrap">January 21,</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=NBC+News&rft.atitle=New+weapon+in+war+on+bird+flu%3A+tiny+bubbles&rft.date=2007-06-10&rft_id=https%3A%2F%2Fwww.nbcnews.com%2Fid%2Fwbna19036479&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-21"><span class="mw-cite-backlink"><b><a href="#cite_ref-21">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFBensonAlphinDawsonMalone2009" class="citation journal cs1">Benson, E.R.; Alphin, R.L.; Dawson, M.D.; Malone, G.W. (May 2009). <a rel="nofollow" class="external text" href="https://linkinghub.elsevier.com/retrieve/pii/S0032579119389229">"Use of water-based foam to depopulate ducks and other species"</a>. <i>Poultry Science</i>. <b>88</b> (5): <span class="nowrap">904–</span>910. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.3382%2Fps.2008-00268">10.3382/ps.2008-00268</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/19359675">19359675</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Poultry+Science&rft.atitle=Use+of+water-based+foam+to+depopulate+ducks+and+other+species&rft.volume=88&rft.issue=5&rft.pages=%3Cspan+class%3D%22nowrap%22%3E904-%3C%2Fspan%3E910&rft.date=2009-05&rft_id=info%3Adoi%2F10.3382%2Fps.2008-00268&rft_id=info%3Apmid%2F19359675&rft.aulast=Benson&rft.aufirst=E.R.&rft.au=Alphin%2C+R.L.&rft.au=Dawson%2C+M.D.&rft.au=Malone%2C+G.W.&rft_id=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0032579119389229&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-22">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFBolotnikova2022" class="citation news cs1">Bolotnikova, Marina (March 8, 2022). <a rel="nofollow" class="external text" href="https://www.theguardian.com/environment/2022/mar/08/theyre-cooking-them-alive-calls-to-ban-cruel-killing-methods-on-us-farms">"<span class="cs1-kern-left"></span>'They're cooking them alive': calls to ban 'cruel' killing methods on US farms"</a>. <i>The Guardian</i>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0261-3077">0261-3077</a><span class="reference-accessdate">. Retrieved <span class="nowrap">January 21,</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Guardian&rft.atitle=%27They%27re+cooking+them+alive%27%3A+calls+to+ban+%27cruel%27+killing+methods+on+US+farms&rft.date=2022-03-08&rft.issn=0261-3077&rft.aulast=Bolotnikova&rft.aufirst=Marina&rft_id=https%3A%2F%2Fwww.theguardian.com%2Fenvironment%2F2022%2Fmar%2F08%2Ftheyre-cooking-them-alive-calls-to-ban-cruel-killing-methods-on-us-farms&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-Gibson-23"><span class="mw-cite-backlink">^ <a href="#cite_ref-Gibson_23-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Gibson_23-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFGibson1999" class="citation book cs1">Gibson, Ashby (1999). <i>Cellular Solids: Structure and Properties</i>. Cambridge, UK: Cambridge University Press. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9781316025420" title="Special:BookSources/9781316025420"><bdi>9781316025420</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Cellular+Solids%3A+Structure+and+Properties&rft.place=Cambridge%2C+UK&rft.pub=Cambridge+University+Press&rft.date=1999&rft.isbn=9781316025420&rft.aulast=Gibson&rft.aufirst=Ashby&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-24"><span class="mw-cite-backlink"><b><a href="#cite_ref-24">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFCarrollKirschman2023" class="citation journal cs1">Carroll, Gregory T.; Kirschman, David L. (January 23, 2023). <a rel="nofollow" class="external text" href="https://pubs.acs.org/doi/10.1021/acs.chas.2c00071">"Catalytic Surgical Smoke Filtration Unit Reduces Formaldehyde Levels in a Simulated Operating Room Environment"</a>. <i>ACS Chemical Health & Safety</i>. <b>30</b> (1): <span class="nowrap">21–</span>28. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1021%2Facs.chas.2c00071">10.1021/acs.chas.2c00071</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/1871-5532">1871-5532</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:255047115">255047115</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=ACS+Chemical+Health+%26+Safety&rft.atitle=Catalytic+Surgical+Smoke+Filtration+Unit+Reduces+Formaldehyde+Levels+in+a+Simulated+Operating+Room+Environment&rft.volume=30&rft.issue=1&rft.pages=%3Cspan+class%3D%22nowrap%22%3E21-%3C%2Fspan%3E28&rft.date=2023-01-23&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A255047115%23id-name%3DS2CID&rft.issn=1871-5532&rft_id=info%3Adoi%2F10.1021%2Facs.chas.2c00071&rft.aulast=Carroll&rft.aufirst=Gregory+T.&rft.au=Kirschman%2C+David+L.&rft_id=https%3A%2F%2Fpubs.acs.org%2Fdoi%2F10.1021%2Facs.chas.2c00071&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-25"><span class="mw-cite-backlink"><b><a href="#cite_ref-25">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFWuAnderssonHolgateJohansson2014" class="citation journal cs1">Wu, Qiong; Andersson, Richard L.; Holgate, Tim; Johansson, Eva; Gedde, Ulf W.; Olsson, Richard T.; Hedenqvist, Mikael S. (2014). <a rel="nofollow" class="external text" href="https://doi.org/10.1039%2FC4TA04787G">"Highly porous flame-retardant and sustainable biofoams based on wheat gluten and in situ polymerized silica"</a>. <i>Journal of Materials Chemistry A</i>. <b>2</b> (48). 20996–21009. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1039%2FC4TA04787G">10.1039/C4TA04787G</a></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Journal+of+Materials+Chemistry+A&rft.atitle=Highly+porous+flame-retardant+and+sustainable+biofoams+based+on+wheat+gluten+and+in+situ+polymerized+silica&rft.volume=2&rft.issue=48&rft.pages=20996-21009&rft.date=2014&rft_id=info%3Adoi%2F10.1039%2FC4TA04787G&rft.aulast=Wu&rft.aufirst=Qiong&rft.au=Andersson%2C+Richard+L.&rft.au=Holgate%2C+Tim&rft.au=Johansson%2C+Eva&rft.au=Gedde%2C+Ulf+W.&rft.au=Olsson%2C+Richard+T.&rft.au=Hedenqvist%2C+Mikael+S.&rft_id=https%3A%2F%2Fdoi.org%2F10.1039%252FC4TA04787G&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-26"><span class="mw-cite-backlink"><b><a href="#cite_ref-26">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFReyes-LabartaMarcilla2008" class="citation journal cs1">Reyes-Labarta, J.A.; Marcilla, A. (2008). "Kinetic Study of the Decompositions Involved in the Thermal Degradation of Commercial Azodicarbonamide". <i>Journal of Applied Polymer Science</i>. <b>107</b> (1): <span class="nowrap">339–</span>346. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1002%2Fapp.26922">10.1002/app.26922</a>. <a href="/wiki/Hdl_(identifier)" class="mw-redirect" title="Hdl (identifier)">hdl</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://hdl.handle.net/10045%2F24682">10045/24682</a></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Journal+of+Applied+Polymer+Science&rft.atitle=Kinetic+Study+of+the+Decompositions+Involved+in+the+Thermal+Degradation+of+Commercial+Azodicarbonamide&rft.volume=107&rft.issue=1&rft.pages=%3Cspan+class%3D%22nowrap%22%3E339-%3C%2Fspan%3E346&rft.date=2008&rft_id=info%3Ahdl%2F10045%2F24682&rft_id=info%3Adoi%2F10.1002%2Fapp.26922&rft.aulast=Reyes-Labarta&rft.aufirst=J.A.&rft.au=Marcilla%2C+A.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-27"><span class="mw-cite-backlink"><b><a href="#cite_ref-27">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFReyes-LabartaMarcilla2012" class="citation journal cs1">Reyes-Labarta, J.A.; Marcilla, A. (2012). "Thermal Treatment and Degradation of Crosslinked Ethylene Vinyl Acetate-Polyethylene-Azodicarbonamide-ZnO Foams. Complete Kinetic Modelling and Analysis". <i>Industrial & Engineering Chemistry Research</i>. <b>51</b> (28): <span class="nowrap">9515–</span>9530. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1021%2Fie3006935">10.1021/ie3006935</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Industrial+%26+Engineering+Chemistry+Research&rft.atitle=Thermal+Treatment+and+Degradation+of+Crosslinked+Ethylene+Vinyl+Acetate-Polyethylene-Azodicarbonamide-ZnO+Foams.+Complete+Kinetic+Modelling+and+Analysis&rft.volume=51&rft.issue=28&rft.pages=%3Cspan+class%3D%22nowrap%22%3E9515-%3C%2Fspan%3E9530&rft.date=2012&rft_id=info%3Adoi%2F10.1021%2Fie3006935&rft.aulast=Reyes-Labarta&rft.aufirst=J.A.&rft.au=Marcilla%2C+A.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-28"><span class="mw-cite-backlink"><b><a href="#cite_ref-28">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFReyes-LabartaMarcilla2008" class="citation journal cs1">Reyes-Labarta, J.A.; Marcilla, A. (2008). "Differential Scanning Calorimetry Analysis of the Thermal Treatment of Ternary Mixtures of Ethylene Vinyl Acetate, Polyethylene and Azodicarbonamide". <i>Journal of Applied Polymer Science</i>. <b>110</b> (5): <span class="nowrap">3217–</span>3224. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1002%2Fapp.28802">10.1002/app.28802</a>. <a href="/wiki/Hdl_(identifier)" class="mw-redirect" title="Hdl (identifier)">hdl</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://hdl.handle.net/10045%2F13312">10045/13312</a></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Journal+of+Applied+Polymer+Science&rft.atitle=Differential+Scanning+Calorimetry+Analysis+of+the+Thermal+Treatment+of+Ternary+Mixtures+of+Ethylene+Vinyl+Acetate%2C+Polyethylene+and+Azodicarbonamide&rft.volume=110&rft.issue=5&rft.pages=%3Cspan+class%3D%22nowrap%22%3E3217-%3C%2Fspan%3E3224&rft.date=2008&rft_id=info%3Ahdl%2F10045%2F13312&rft_id=info%3Adoi%2F10.1002%2Fapp.28802&rft.aulast=Reyes-Labarta&rft.aufirst=J.A.&rft.au=Marcilla%2C+A.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-29"><span class="mw-cite-backlink"><b><a href="#cite_ref-29">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFReyes-LabartaOlayaMarcilla2006" class="citation journal cs1">Reyes-Labarta, J.A.; Olaya, M.M.; Marcilla, A. (2006). "DSC Study of the Transitions Involved in the Thermal Treatment of Foamable Mixtures of PE and EVA Copolymer with Azodicarbonamide". <i>Journal of Applied Polymer Science</i>. <b>102</b> (3): <span class="nowrap">2015–</span>2025. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1002%2Fapp.23969">10.1002/app.23969</a>. <a href="/wiki/Hdl_(identifier)" class="mw-redirect" title="Hdl (identifier)">hdl</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://hdl.handle.net/10045%2F24680">10045/24680</a></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Journal+of+Applied+Polymer+Science&rft.atitle=DSC+Study+of+the+Transitions+Involved+in+the+Thermal+Treatment+of+Foamable+Mixtures+of+PE+and+EVA+Copolymer+with+Azodicarbonamide&rft.volume=102&rft.issue=3&rft.pages=%3Cspan+class%3D%22nowrap%22%3E2015-%3C%2Fspan%3E2025&rft.date=2006&rft_id=info%3Ahdl%2F10045%2F24680&rft_id=info%3Adoi%2F10.1002%2Fapp.23969&rft.aulast=Reyes-Labarta&rft.aufirst=J.A.&rft.au=Olaya%2C+M.M.&rft.au=Marcilla%2C+A.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> <li id="cite_note-30"><span class="mw-cite-backlink"><b><a href="#cite_ref-30">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFAshida2006" class="citation book cs1">Ashida, Kaneyoshi (2006). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=IQUd-3aKSD4C"><i>Polyurethane and related foams: chemistry and technology</i></a>. CRC Press. pp. <span class="nowrap">79–</span>81. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-1-58716-159-9" title="Special:BookSources/978-1-58716-159-9"><bdi>978-1-58716-159-9</bdi></a>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20170217110121/https://books.google.com/books?id=IQUd-3aKSD4C">Archived</a> from the original on February 17, 2017.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Polyurethane+and+related+foams%3A+chemistry+and+technology&rft.pages=%3Cspan+class%3D%22nowrap%22%3E79-%3C%2Fspan%3E81&rft.pub=CRC+Press&rft.date=2006&rft.isbn=978-1-58716-159-9&rft.aulast=Ashida&rft.aufirst=Kaneyoshi&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DIQUd-3aKSD4C&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></span> </li> </ol></div> <div class="mw-heading mw-heading2"><h2 id="Further_reading">Further reading</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=22" title="Edit section: Further reading"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFWeaireHutzler1999" class="citation book cs1">Weaire, D.L.; Hutzler, Stefan (1999). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=mEHlZ9ZodFsC"><i>The Physics of Foams</i></a>. Oxford, England: Oxford University Press. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0198510977" title="Special:BookSources/0198510977"><bdi>0198510977</bdi></a><span class="reference-accessdate">. Retrieved <span class="nowrap">August 30,</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Physics+of+Foams&rft.place=Oxford%2C+England&rft.pub=Oxford+University+Press&rft.date=1999&rft.isbn=0198510977&rft.aulast=Weaire&rft.aufirst=D.L.&rft.au=Hutzler%2C+Stefan&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DmEHlZ9ZodFsC&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span> A modern treatise almost exclusively focused on liquid foams.</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFGibsonAshby1997" class="citation book cs1">Gibson, Lorna J.; Ashby, Michael F. (1997). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=IySUr5sn4N8C"><i>Cellular Solids: Structure and Properties</i></a>. Cambridge Solid State Science. Cambridge, England: Cambridge University Press. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0521499119" title="Special:BookSources/0521499119"><bdi>0521499119</bdi></a><span class="reference-accessdate">. Retrieved <span class="nowrap">August 30,</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Cellular+Solids%3A+Structure+and+Properties&rft.place=Cambridge%2C+England&rft.series=Cambridge+Solid+State+Science&rft.pub=Cambridge+University+Press&rft.date=1997&rft.isbn=0521499119&rft.aulast=Gibson&rft.aufirst=Lorna+J.&rft.au=Ashby%2C+Michael+F.&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DIySUr5sn4N8C&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span> A treatise termed a classic by Weaire & Hutzler (1999), on solid foams, and the reason they limit their focus to liquid foams.</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFCantat,_ICohen-Addad,_SElias,_FGraner,_F2013" class="citation book cs1"><a href="/wiki/Isabelle_Cantat" title="Isabelle Cantat">Cantat, I</a>; Cohen-Addad, S; Elias, F; Graner, F; Höhler, R; Pitois, O; Rouyer, F; Saint-Jalmes, A (2013). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=Ndzzl1hUNRoC"><i>Foams: Structure and Dynamics</i></a>. Oxford, England: Oxford University Press. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0199662890" title="Special:BookSources/978-0199662890"><bdi>978-0199662890</bdi></a><span class="reference-accessdate">. Retrieved <span class="nowrap">August 30,</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Foams%3A+Structure+and+Dynamics&rft.place=Oxford%2C+England&rft.pub=Oxford+University+Press&rft.date=2013&rft.isbn=978-0199662890&rft.au=Cantat%2C+I&rft.au=Cohen-Addad%2C+S&rft.au=Elias%2C+F&rft.au=Graner%2C+F&rft.au=H%C3%B6hler%2C+R&rft.au=Pitois%2C+O&rft.au=Rouyer%2C+F&rft.au=Saint-Jalmes%2C+A&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DNdzzl1hUNRoC&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span> Note, this source also focuses on liquid foams.</li> <li>Thomas Hipke, Günther Lange, René Poss: Taschenbuch für Aluminiumschäume. Aluminium-Verlag, Düsseldorf 2007, <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-3-87017-285-5" title="Special:BookSources/978-3-87017-285-5">978-3-87017-285-5</a>.</li> <li>Hannelore Dittmar-Ilgen: Metalle lernen schwimmen. In: Dies.: Wie der Kork-Krümel ans Weinglas kommt. Hirzel, Stuttgart 2006, <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-3-7776-1440-3" title="Special:BookSources/978-3-7776-1440-3">978-3-7776-1440-3</a>, S. 74.</li></ul> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Foam&action=edit&section=23" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1235681985">.mw-parser-output .side-box{margin:4px 0;box-sizing:border-box;border:1px solid #aaa;font-size:88%;line-height:1.25em;background-color:var(--background-color-interactive-subtle,#f8f9fa);display:flow-root}.mw-parser-output .side-box-abovebelow,.mw-parser-output .side-box-text{padding:0.25em 0.9em}.mw-parser-output .side-box-image{padding:2px 0 2px 0.9em;text-align:center}.mw-parser-output .side-box-imageright{padding:2px 0.9em 2px 0;text-align:center}@media(min-width:500px){.mw-parser-output .side-box-flex{display:flex;align-items:center}.mw-parser-output .side-box-text{flex:1;min-width:0}}@media(min-width:720px){.mw-parser-output .side-box{width:238px}.mw-parser-output .side-box-right{clear:right;float:right;margin-left:1em}.mw-parser-output .side-box-left{margin-right:1em}}</style><style data-mw-deduplicate="TemplateStyles:r1237033735">@media print{body.ns-0 .mw-parser-output .sistersitebox{display:none!important}}@media screen{html.skin-theme-clientpref-night .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}</style><div class="side-box side-box-right plainlinks sistersitebox"><style data-mw-deduplicate="TemplateStyles:r1126788409">.mw-parser-output .plainlist ol,.mw-parser-output .plainlist ul{line-height:inherit;list-style:none;margin:0;padding:0}.mw-parser-output .plainlist ol li,.mw-parser-output .plainlist ul li{margin-bottom:0}</style> <div class="side-box-flex"> <div class="side-box-image"><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Wiktionary-logo-en-v2.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/9/99/Wiktionary-logo-en-v2.svg/40px-Wiktionary-logo-en-v2.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/9/99/Wiktionary-logo-en-v2.svg/60px-Wiktionary-logo-en-v2.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/9/99/Wiktionary-logo-en-v2.svg/120px-Wiktionary-logo-en-v2.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span></div> <div class="side-box-text plainlist">Look up <i><b><a href="https://en.wiktionary.org/wiki/Special:Search/foam" class="extiw" title="wiktionary:Special:Search/foam">foam</a></b></i> in Wiktionary, the free dictionary.</div></div> </div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1235681985" /><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1237033735" /><div class="side-box side-box-right plainlinks sistersitebox"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1126788409" /> <div class="side-box-flex"> <div class="side-box-image"><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Commons-logo.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/40px-Commons-logo.svg.png" decoding="async" width="30" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/60px-Commons-logo.svg.png 1.5x" data-file-width="1024" data-file-height="1376" /></a></span></div> <div class="side-box-text plainlist">Wikimedia Commons has media related to <span style="font-weight: bold; font-style: italic;"><a href="https://commons.wikimedia.org/wiki/Category:Foam" class="extiw" title="commons:Category:Foam">Foam</a></span>.</div></div> </div> <ul><li>Andrew M. Kraynik, Douglas A. Reinelt, Frank van Swol <a rel="nofollow" class="external text" href="https://web.archive.org/web/20160804103003/http://www.aquafoam.com/papers/Kraynik.pdf">Structure of random monodisperse foam</a></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFMoriarty2010" class="citation web cs1">Moriarty, Philip (2010). <a rel="nofollow" class="external text" href="http://www.sixtysymbols.com/videos/foam.htm">"Foam Physics"</a>. <i>Sixty Symbols</i>. <a href="/wiki/Brady_Haran" title="Brady Haran">Brady Haran</a> for the <a href="/wiki/University_of_Nottingham" title="University of Nottingham">University of Nottingham</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Sixty+Symbols&rft.atitle=Foam+Physics&rft.date=2010&rft.aulast=Moriarty&rft.aufirst=Philip&rft_id=http%3A%2F%2Fwww.sixtysymbols.com%2Fvideos%2Ffoam.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFoam" class="Z3988"></span></li></ul> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374" /><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235" /></div><div role="navigation" class="navbox" aria-labelledby="Patterns_in_nature49" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="3"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374" /><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231" /><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Patterns_in_nature" title="Template:Patterns in nature"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Patterns_in_nature" title="Template talk:Patterns in nature"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Patterns_in_nature" title="Special:EditPage/Template:Patterns in nature"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Patterns_in_nature49" style="font-size:114%;margin:0 4em"><a href="/wiki/Patterns_in_nature" title="Patterns in nature">Patterns in nature</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">Patterns</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Fracture" title="Fracture">Crack</a></li> <li><a href="/wiki/Dune" title="Dune">Dune</a></li> <li><a class="mw-selflink selflink">Foam</a></li> <li><a href="/wiki/Meander" title="Meander">Meander</a></li> <li><a href="/wiki/Parastichy" title="Parastichy">Parastichy</a></li> <li><a href="/wiki/Phyllotaxis" title="Phyllotaxis">Phyllotaxis</a></li> <li><a href="/wiki/Soap_bubble" title="Soap bubble">Soap bubble</a></li> <li><a href="/wiki/Symmetry" title="Symmetry">Symmetry</a> <ul><li><a href="/wiki/Crystal_structure" title="Crystal structure">in crystals</a></li> <li><a href="/wiki/Quasicrystal" title="Quasicrystal">Quasicrystals</a></li> <li><a href="/wiki/Floral_symmetry" title="Floral symmetry">in flowers</a></li> <li><a href="/wiki/Symmetry_in_biology" title="Symmetry in biology">in biology</a></li></ul></li> <li><a href="/wiki/Tessellation" title="Tessellation">Tessellation</a></li> <li><a href="/wiki/K%C3%A1rm%C3%A1n_vortex_street" title="Kármán vortex street">Vortex street</a></li> <li><a href="/wiki/Wave" title="Wave">Wave</a></li> <li><a href="/wiki/Widmanst%C3%A4tten_pattern" title="Widmanstätten pattern">Widmanstätten pattern</a></li></ul> </div></td><td class="noviewer navbox-image" rowspan="4" style="width:1px;padding:0 0 0 2px"><div><span typeof="mw:File"><a href="/wiki/File:Yemen_Chameleon_(cropped).jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Yemen_Chameleon_%28cropped%29.jpg/80px-Yemen_Chameleon_%28cropped%29.jpg" decoding="async" width="80" height="54" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Yemen_Chameleon_%28cropped%29.jpg/120px-Yemen_Chameleon_%28cropped%29.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Yemen_Chameleon_%28cropped%29.jpg/160px-Yemen_Chameleon_%28cropped%29.jpg 2x" data-file-width="2086" data-file-height="1411" /></a></span></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Causes</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Pattern_formation" title="Pattern formation">Pattern formation</a></li> <li><a href="/wiki/Biology" title="Biology">Biology</a> <ul><li><a href="/wiki/Natural_selection" title="Natural selection">Natural selection</a></li> <li><a href="/wiki/Camouflage" title="Camouflage">Camouflage</a></li> <li><a href="/wiki/Mimicry" title="Mimicry">Mimicry</a></li> <li><a href="/wiki/Sexual_selection" title="Sexual selection">Sexual selection</a></li></ul></li> <li><a href="/wiki/Mathematics" title="Mathematics">Mathematics</a> <ul><li><a href="/wiki/Chaos_theory" title="Chaos theory">Chaos theory</a></li> <li><a href="/wiki/Fractal" title="Fractal">Fractal</a></li> <li><a href="/wiki/Logarithmic_spiral" title="Logarithmic spiral">Logarithmic spiral</a></li></ul></li> <li><a href="/wiki/Physics" title="Physics">Physics</a> <ul><li><a href="/wiki/Crystal" title="Crystal">Crystal</a></li> <li><a href="/wiki/Fluid_dynamics" title="Fluid dynamics">Fluid dynamics</a></li> <li><a href="/wiki/Plateau%27s_laws" title="Plateau's laws">Plateau's laws</a></li> <li><a href="/wiki/Self-organization" title="Self-organization">Self-organization</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">People</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Plato" title="Plato">Plato</a></li> <li><a href="/wiki/Pythagoras" title="Pythagoras">Pythagoras</a></li> <li><a href="/wiki/Empedocles" title="Empedocles">Empedocles</a></li> <li><a href="/wiki/Fibonacci" title="Fibonacci">Fibonacci</a> <ul><li><i><a href="/wiki/Liber_Abaci" title="Liber Abaci">Liber Abaci</a></i></li></ul></li> <li><a href="/wiki/Adolf_Zeising" title="Adolf Zeising">Adolf Zeising</a></li> <li><a href="/wiki/Ernst_Haeckel" title="Ernst Haeckel">Ernst Haeckel</a></li> <li><a href="/wiki/Joseph_Plateau" title="Joseph Plateau">Joseph Plateau</a></li> <li><a href="/wiki/Wilson_Bentley" title="Wilson Bentley">Wilson Bentley</a></li> <li><a href="/wiki/D%27Arcy_Wentworth_Thompson" title="D'Arcy Wentworth Thompson">D'Arcy Wentworth Thompson</a> <ul><li><i><a href="/wiki/On_Growth_and_Form" title="On Growth and Form">On Growth and Form</a></i></li></ul></li> <li><a href="/wiki/Alan_Turing" title="Alan Turing">Alan Turing</a> <ul><li><i><a href="/wiki/The_Chemical_Basis_of_Morphogenesis" title="The Chemical Basis of Morphogenesis">The Chemical Basis of Morphogenesis</a></i></li></ul></li> <li><a href="/wiki/Aristid_Lindenmayer" title="Aristid Lindenmayer">Aristid Lindenmayer</a></li> <li><a href="/wiki/Benoit_Mandelbrot" title="Benoit Mandelbrot">Benoît Mandelbrot</a> <ul><li><i><a href="/wiki/How_Long_Is_the_Coast_of_Britain%3F_Statistical_Self-Similarity_and_Fractional_Dimension" class="mw-redirect" title="How Long Is the Coast of Britain? Statistical Self-Similarity and Fractional Dimension">How Long Is the Coast of Britain? Statistical Self-Similarity and Fractional Dimension</a></i></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Related</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Pattern_recognition_(psychology)" title="Pattern recognition (psychology)">Pattern recognition</a></li> <li><a href="/wiki/Emergence" title="Emergence">Emergence</a></li> <li><a href="/wiki/Mathematics_and_art" title="Mathematics and art">Mathematics and art</a></li></ul> </div></td></tr></tbody></table></div>    </div><noscript><img src="https://auth.wikimedia.org/loginwiki/wiki/Special:CentralAutoLogin/start?useformat=desktop&type=1x1&usesul3=1" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" 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