资源描述:
《synthesis of mesoporous materials:介孔材料的合成》由会员上传分享,免费在线阅读,更多相关内容在应用文档-天天文库。
1、JuliaHoetsSynthesisofMesoporousMaterialsMesoporousmaterialsarethosewithporesintherange20-500Åindiameter.1www.mesoporous.com,InternationalMesostructuredMaterialAssociation.(FromYahoosearchengine.)Theyhavehugesurfaceareas,providingavastnumberofsiteswheresorptionprocessescanoccur.Thesemater
2、ialshavenumerousapplicationsincatalysis,separationandmanyotherfields.2Davies,S.,Goltner,C.,MesoporousSilicafromSupramolecularTemplating,UniversityofBristol,InorganicPractical–levelII,experiment8.(Fromrelevantpracticalhandout.)Thesynthesisofthesematerialsisthereforeofconsiderableinteresta
3、ndisconstantlybeingdevelopedtointroducedifferentproperties.Originallyporositywasintroducedtolayeredsystemsbypillaring.Thisprocessinvolvestheintercalationofaguestspeciestocreateaporousnetwork.3Schöllhorn,R.,IntercalationSystemsasNanostructuredFunctionalMaterials,Chem.Mater.,1996,8,1747-17
4、57.(Fromlistofreferencesinreferencenumber13.)However,theinterlayervoidswouldcollapseonremovaloftheguestspecies,sopillarswereintroducedtotheframeworktomaintainthelateralspacing.Poresizecouldthusbecontrolledbythesizeofthepillar.Thespacinginmaterialssynthesisedinthisfashionwashoweverirregul
5、arandthesizedistributionbroad.In1992researchersatMobildemonstratedthesynthesisofhexagonallypackedmesoporoussilicateandaluminosilicatematerialswithuniformporesizes,evenlydistributedthroughoutthematerial.4Kresge,C.T.etal.OrderedMesoporousMolecularSievesSynthesisedbyaLiquidCrystalTemplateMe
6、chanism,Nature,1992,359,710-712.(Startingreference–given.)5Beck,J.S.etal.ANewFamilyofMesoporousMolecularSievesPreparedwithLiquidCrystalTemplates,J.Am.Chem.Soc.,1992,114,10834-10843.(Startingreference–given.)ThesematerialsweretermedMCM-41.Theirsynthesiswasachievedbytheuseofsurfactantmicel
7、lesasstructuredirectingagentsinasol-gelprocess.Amphiphillicsurfactantsselfassembleintocylindricalmicelles,whichareencapsulatedbyaninorganicmaterial(silicateoraluminosilicateinthiscase),whichbalancesthechargeonthemicellularsurfaces.Calcination,athermalprocessingtechniqueis