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1、3DDesignofself-assemblednanoporouscolloidsa,b,caI.SokolovandY.KievskyaDepartmentofPhysics,ClarksonUniversity,Potsdam,NY,13699-5820,USAbDepartmentofChemistry,ClarksonUniversity,Potsdam,NY,13699-5810,USAcCenterforAdvancedMaterialProcessing(CAMP),ClarksonUniversity,Potsdam,NY,13699-5665,USARecentlyd
2、iscoveredsynthesisofunusualcurvednanoporoussilicashapes,suchasrods,discoids,spheres,tubes,andhollowhelicoids,havebroughtforththeproblemofunderstandingtheformationmechanism.Knowledgeofsuchmechanismmayleadtotheabilitytocontrolthenanoporousshapes.Thisisimportantinavarietyofapplicationsandnewtechnolo
3、gieswherenanostructureandgeometrydeterminefunction.Inthisworktheproblemofmorphogenesisofnanoporoussilicashapesisanalyzed.Atheoreticalbasisisoutlinedtodescribethevarietyofformsandsurfacedesignsthatresultfromtheliquidcrystalstage,silicificationandrigidificationofshapes.Furtherexperimentalevidencein
4、favorofthesuggestedmechanismsispresented.1.INTRODUCTIONWiththediscoveryoftheliquidcrystaltemplating(see,e.g.,[1,2],areview[3]andotherreferencescitedthere)ofhexagonal,cubicandlamellarnano(meso)structuredsilica,materialssciencehasmovedintotheareaofdesignandsynthesisofinorganicswithcomplexform.Itisp
5、ossibletosynthesizeinorganicswithstructuralfeaturesofafewnanometersandarchitecturesoverratherlargelengthscales,uptohundredsofmicrons.Thisnanochemistryisinspiringresearchinmaterialsscience,solidstatechemistry,semiconductorphysics,biomimetics,andbiomaterials[3–26].Variousamphiphilescanbeorganizedin
6、tosupramolecularassembliesandtogetherwitharangeofinorganicprecursorscreatealargenumberofcompositemesostructures.Manipulationofsurfactantpackingparameter,headgroupcharge,co-surfactants,solvents,co-solvents,andorganicadditiveshavebeenusedtotemplateparticularmesostructures.Dimensionoftheporescanbetu
7、nedwithangstromprecisionoverthesizerangeof20-100Å(see,e.g.,[8]).Distincttemplatingmechanismsofinorganicmesostructuresbaseduponcationic,anionicandneutralsurfactantassemblieshavealsobeenstudied,see,e.g.,[5,27,28].Nanosca