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简介：Poly（aryleneetherdiketone）swerepreparedbythearomaticnucleophilicdisplacementreactionof4,4’-difluorobenzilwithdifferentbisphenolsinthepresenceofan-hydrouspotassiumcarbonateindiphenylsulfoneatelevatedtemperature.Thepolymersobtainedhadinherentviscosityof0.51～0.63dL/g,andexhibitedglasstransitiontemper-aturerangingfrom136～217℃mainlydependingonthebisphenolsusedinthepolymersynthesis.Thermogravimetryofthesepolymersshowedexcellentthermalstability,indi-catingthat10%weightlossesofthepolymerswereobservedintherangeabove428℃and438℃inairandnitrogen,respectively.ThemechanicalpropertiesofthesepolymerswerealsodescribedandthepermeabilityoffivepolymersforH2,O2andN2wasdeterminedat30℃.

简介：Bythereactionofpoly(bromoacetylstyrene)(EBPS)withthiaurea(TU),akindofnovelchelatingresinwithheterocyaclicringofsulfurandnitrogen,poly[4-(2-amino)thiazoleyl-4-vinylben=ene],wassynthesized.ItsstructurewascharacterizedbyFTIRandelementalanalysis.Thefactorswhichhaveinfluenceonthereactionsuchasreactiontime,solvents,andmolarratioofreactantswereinvestigated.

简介：Inthispaper,MPt/C(M=La,Nd)catalystsofPEMFCweresynthesizedbymicrowaveradiationprocess.ThecrystallinityandstructureofcatalystswererespectivelyanalyzedbyXRDandnitrogenadsorptiontests.Theactivityofcatalystswasinvestigatedbyelectrochemistryexperiment.Theresultsshowedthat:1)comparedwithPt/Ccatalystpreparedbytypicalimpregnation-reductionprocess,thesizeofMPt/CcatalystparticledecreasedandtheavailablecrystalforO2reductionincreased;2)theMPt/CcatalystshadrelativelyhighBETsurfaceareas;and3)thesecrystaltransformationsoftheMPt/Ccatalystbroughthightheelectrocatalyticactivity,andasaresult,improvedthepowerofPEMFC.

简介：Electrostaticlayer-by-layerself-assemblymultilayerfilmsweresuccessfullyfabricatedfromC60-ethylenediamineadduct(C60-EDA)andDNA.Undervisiblelightirradiation,DNAisreadytobecleavedandthefilmsaredestroyed.

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简介：Ithasbeenwellknownthatfluorinatedpolyurethanesexhibituniquelylowsurfaceenergy,biocompatibilityandbiostability,thermalandoxidativestabilityandnonstickingbehavior.Consequently,thesepolymershaveattractedconsiderableinterest.However,themechanicalpropertiesoffluorinatedpolyurethanesusuallydeclinewithincreasingfluorinecontents.Theblendingoffluorinatedpolyurethaneswithnormalpolyurethanewascarriedouttoachievebalancedmechanicalandsurfaceproperties.Itwasfoundthatpolyurethanewithgoodmechanicalpropertiesandlowsurfaceenergycanbeobtainedbyaddingasmallamountoffluorinatedpolyurethane.Thefluorinatedsidechainscaneasilymigratetouppermostsurfacesoftheblendsuntillthefluorinelevelatthesurfacebecomesalmostsaturated.Ithasbeenshownfromcontactangle,XPSandAFMmeasurementsthatonlyaslittleas0.34wt%offluorinelevelisenoughtoproduceasurfacesaturatedwithfluorine,andthefluorinelevelattheuppermostsurfaceisonehundredtimeshigherthanthatintheblendbulk.Thefinaloutersurfacestructuresofthepolyurethaneblendwereindependentofthecontentofthefluorinatedpolyurethaneintheblendsduetothesurfacessaturatedbyfluorine.

简介：Inthispaper,anewthin-layerion-exchangeresinphaseanalyticalmethodisintroduced.Itisbasedonthat,thebismuthouscationcanassociatewithiodicanions,soastoformedananioncomplex[BiI4-_]inastrongacidicenvironments.Thisanioncomplexcanalsoexchangeswithaweakeranionsonthesurfaceactivesiteofanionexchangeresin,sothata[R+][Bil4-]solidphasebinaryassociationalsystemisproduced.Owingtothesolidsystemisagreatmanydispersiveparticulates,itcanbepressedtoathin-layerbypresstoolsofthesocalled"thin-layerresinphase"or"resinphase",andusingthissolidassociationsystemspectrophotometryforthedeterminationoftracemetals.Soitcanincreasetheanalyticalsensitivity.Thisassociationsystemexhibitsmaximumabsorbanceat460nm,andobeysBeer'slawovertheconcentrationrange0.0lug/ml-l.20ug/mlofbismuthous(lll),hhasamolarabsorptivityof7.1×l^5[L/mol.cm].itindicatedtheresinphasespectrophotometryisasensitiveanalyticalmethodfortracebismuthous.Itis18timeshigherthanroutineaqueousspectrophotometry.Therelativestandarddeviationsis1.82%(n=6)fortheFfmeasurementsof0.Sug/mlBi(llO.ThedetectionlimitofBismuthous(lll)is1.4XlO~mol/L.ThemethodhasappliedtotheanalysisBi(lll)inenvironmentalwatersamples.

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简介：Polyolefinsthatbearachiralsidechain(typicallyanisobutylgroup)experienceaso-calledmacromolecularamplificationofchirality:thechiralside-chaininducesaslightpreferenceforeithertgortg-mainchainconformation.Thisslightconformationalbiasisamplifiedcooperativelyalongthechain,andresultsinpreferredchiralityofthemainchainhelicalconformations.Asaresult,thesepolymersdisplayaliquid-crystal(LC)phasebothinsolutionand,inthemeltasatransientphaseonthewaytocrystallization.Theexistenceoftwoprocesses(melt-LCandLC-crystaltransitions)resultsinunconventionalbehaviorsthatwerefirstanalyzedbyPinoandcollaboratorsbackin1975.Thesepolymersalsoofferameanstotestthestructuralconsequencesofrecentlyintroducedcrystallizationschemes.Theseschemespostulatetheformationofatransientliquid-crystalphaseasageneralschemeforpolymercrystallization.

简介：Linearpolysiloxaneswithpendantbenzo-15-crown-5moietieshavebeensynthesizedfrom3′-or4′-allylbenzo-15-C-5viahydrosilylationofmethyldichlorosilane,followedbypolycondensationwithsilanol-terminatedpolydimethylsiloxane.Itwasfoundthatthepolysiloxanescouldbeusedascarriersinbulkliquidmembranetotransportions.Factorsinfluencingtransportratehavebeeninvestigated.

简介：Ourobjectivesweretodevelopanewchemicalmethodforthepolymerizationofpyrrole.CuCl2dissolvedinC2H5OHsolventisprimarilyusedfortheinitiationpolymerizationofpyrrole.ThepolymerswithdifferentyieldandconductivitywereobtainedbyraringtheinitialconcentrationofCu2+.TheinitialconcentrationsofCu2+variedfrom1.2×10-4moleto6.48×10-3moleCu2+with2.16×10-2molepyrrole.Thepolypyrroleobtainedwascharacterizedwithelementalanalyzer,XPS,IRspectroscopy,Four-pointprobeandSEM.

简介：Thecopolymerizationofp-diethynylbenzene（PDEB）withphenylacetylene（PhA）,4,4’-diethynylbiphenyl（DEBP）orm-diethynylbenzene（MDEB）arestudiedbyvaryingmoleratiosofmonomers.WhenthemoleratiosofPDEB/PhAarelessorequalto1/5,thecopolymersaresolubleandfusible,buttheothercopolymersareinsolubleandinfusible.Theresultsshowthatthegoodsolventofcross-linkedcopolymersisbenzeneandtheirsolubilityparameteris9.15cal0.5.cm（-1.5）.Andtheirswellability（θp）,Hugginsparameter（χ）,density(d425)andtheaveragemolecularweightsbetweencrosslinks（c）aremeasured.Itisfoundthatθpandcofcopolymersaregreaterbutd425islessthanthatofrespectivehomopolymers.IRspectrashowthatthecopolymershavetransoidconfigurationandsmallnumberofunreactedethynylgroupsexistinthecopolymers.Themechanismaboutthepolymerizationoracetylenicderivativesinitiatedby（Ph3P）2PdCl2isdiscussed.

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简介：Asidechainliquidcrystallinecopolysiloxane,whichwouldshowelectro-opticeffectsasknownfromlowmassliquidcrystal,wassynthesizedbyhydrosilylationreaction,andthetwohomologousmonomerswithdifferentlengthspacerscontainingSchiff’sbasemesogenwith—NO2terminatedgroupweregraftedtoapolysiloxanemainchain.Residualmonomerincrudeproductiseffectiveinreinforcingtheresponsetoanelectricfieldoverthatofpurepolymericliquidcrystal.