学科分类
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109 个结果
  • 简介:Usingpolyvinylalcohol(PVA)asrawmaterialandvacuumpumpoilasoilphasemedium,PVA-basedmicrocarrierswerepreparedbysuspensionmethodThediametersofthebeadswere100-180μm.LO2cellswereculturedonPVA-basedmicrocarriersandcytodexⅢmicrocarriers.Morphology,attachmentandgrowthrateofLO2cellswerestudied.

  • 标签: 聚乙烯醇 LO2细胞 培养
  • 简介:TiO_2-coatedpolystyrenenanoparticleswerepreparedinasimpleway.First,functionalPSparticlesweresynthesizedbycopolymerizingonekindofpolymerizablesurfactantwithstyrene.Thenthestabledispersionsofpolystyrenenanoparticleswereusedastemplates,andpolystyrenenanoparticleswerecoatedwithtitaniabyinsituhydrolysisoftetra-n-butyltitanate(TBT).Nosurfacetreatmentandcentrifugation/redispersioncycleprocesswereneededduringthewholeexperiment.IsolatedPSsphereswithuni...

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  • 简介:TheeffectsofHDPEmatrixtoughnessonthebrittle-ductiletransitionofHDPE/CaCO3blendsareinvestigated.NotallHDPEcanbetoughenedbyCaCO3particles.TheabilityofthematrixtoyieldplaysafundamentalroleindetermingwhetherHDPEcanbetoughenedornot.Thereexistsacriticalmatrixtoughness(Isc≈45J/m)belowwhichHDPEcannotbetoughenedobservablybyCaCO3particleatgivenaveragesize,andabovewhichthecriticalmatrixligamentthickness(τ?)isproportionaltomatriximpactstrength.

  • 标签: MATRIX TOUGHNESS Critical MATRIX ligament thickness
  • 简介:Thechemicalgraftingofthiolterminatedpoly(sodiumstyrenesulfonate)(HS-PSSS)chainsfromsodiumnitrate(NaNO3)saltsolutiontoagoldsurfacewasinvestigatedwithaquartzcrystalmicrobalancewithdissipationmonitoring(QCM-D)indifferentsaltconcentrations.ItwasfoundthatatlowsaltconcentrationgraftingdensityofHS-PSSSwaslowandthegraftedchainsadoptedamushroomconformation.Withtheincreaseofsaltconcentrationpolyelectrolytechainsunderwentatransitiontowardcoiledstateduetoreductionofelectrostaticrepulsionandasaresultmorechainsweregraftedonthesurface.WhenthegraftingdensityreachedacertainlimitafterwhichfurthergraftingcausedrepulsionbetweenalreadygraftedHS-PSSSchainsandasaresultgraftedchainsadoptedabrushconformation.

  • 标签: 表面接枝 硝酸钠 盐溶液 苯乙烯 金表面 石英晶体微天平
  • 简介:OrganicchelatingreagentinfluencesupontheredoxadsorptionofactivatedcarbonfibertowardsAu3-weresystematicallyinvestigated.TheexperimentalresultsindicatedthatthepresenceoforganicchelatingreagentonactivatedcarbonfiberstronglyaffectsadsorptioncapacityofactivatedcarbonfibertowardsAu3+.Thereduction-adsorptionamountofAu3+increasedthreetimesbythepresenceof8-quinolinol.Furthermore,Thereduction-adsorptionamountofAu3+dependedonthepHvalueofadsorptionandtemperature.

  • 标签: AU^3+ 活性炭纤维 有机螯合试剂 氧化吸附 金离子 还原吸附
  • 简介:Solublepoly(3-hexyl-2,5-thienylenevinylene)(PHTV)wasreadilysynthesizedfromthiopheneinayieldbetterthanthatoftheprecursormethodtopreparepoly(thienylenevinylene)(PTV).Thebandgapofthepolymerisabout1.8eV,whichiscomparablewiththatofPTV.Owingtotheintroductionofalkylsidegroupsontothebackboneofthepolymer,itcanbedissolvedincommonorganicsolventssuchaschloroform,THFandtoluene.ThesynthesisofsolublePHTVisaveryimportantapproachtopreventingoxidationandtoimprovingthepropertiesandtheprocessbilityofthePTV.TheexistenceofalkylsidegroupsinPHTVdoesnotaffectits,bandgapandthermalpropertiesascomparedwithPTV.AfterdopingwithFeCl3,theconductivityofPHTVisashighas1.1×10-2S/cm.ThesolublePHTVcanbeeasilytransformedintothinfilmwithmuchbetterqualitythanthatofthePTVfilmpreparedbythetraditionalprecursormethod,whichisveryimportantforfabricatingdeviceswithgoodproperties.

  • 标签: Poly(3-hexyl-2 5-thienylene vinylene) Solubility CONJUGATED polymer
  • 简介:DistributionofmetalsonPd-SnO2/D3520catalystsandstateofthecatalystswrerstudiedwithSEM,XRD.TheinteractionbetweenmetalsandsupportorbetweenPdandSnorPbwerestudiedbyIR,XPS.Inaddition,therelationshipoftheactivityforcatalytichydrogenationoftheolefinsandouterlayervalenceelectrondensityofPdwasdiscussed.Theresultsshowedthatthesecatalystshadsuitablesurfacestate,themetalswereuniformlydispersedonthesurfacelayerofthesupport.Therewerenotobviousinteractionbetweenthemetalsandthesupport.TherewasstronginteractionbetweenPdandSn(orPb)inthecatalysts.ThecatalyticactivityforhydrogenationwasrelatedtoouterlayervalenceelectrondensityofPd.

  • 标签: 结构 D3520催化剂 二氧化锡
  • 简介:DistributionofmetalsonPd-SnO2/D3520catalystsandstateofthecatalystswerestudiedwithSEM,XRD.TheinteractionbetweenmetalsandsupportorbetweenPdandSnorPbwerestudiedbyIR,XPS.Inaddition,therelationshipoftheactivityforcatalytichydrogenationoftheolefinsandouterlayervalenceelectrondensityofPdwasdiscussed.Theresultsshowedthatthesecatalystshadsuitablesurfacestate,themetalswereuniformlydispersedonthesurfacelayerofthesupport.Therewerenotobviousinteractionbetweenthemetalsandthesupport.TherewasstronginteractionbetweenPdandSn(orPb)inthecatalysts.ThecatalyticactivityforhydrogenationwasrelatedtoouterlayervalenceelectrondensityofPd.

  • 标签: 结构特征 二氧化锡 D3520催化剂
  • 简介:包含1,3,4-oxadiazole单位的热地稳定的聚合物作为溶剂在pyridine与芳香/脂肪族的二度酸氯化物通过芳香/脂肪族的bis-tetrazole混合物的Huisgen反应被综合了。获得的聚合物甚至在象DMSO和DMF那样的极的aprotic溶剂不可溶解或稍微可溶。相对高的固有的粘性价值(0.611.33dL/g,在在25点的0.125%H2SO4????????????????????????倠??

  • 标签: 芳香族聚合物 热稳定性 恶二唑 反应 玻璃化转变温度 非质子溶剂
  • 简介:Acylationreactionofanthracenewithoxalylchlorideinthepresenceof[Emim]C1-A1C13ionicliquidhasbeeninvestigated.Pure1,2-aceanthryenedione,whichisusedasintermediateoffunctionalaromaticpolymermaterial,wasobtainedbyrecrystallingthereactionmixturewithaetherandwasdeterminedbyGC/MS,1HNMRandFTIRanalysis.Theinfluencesofvariousparameters,suchasthecontentsofAlCl3in[Emim]C1-A1C13,theamountofacylationagent,amountof[Emim]C1-A1C13,reactiontemperatureandreactiontimewereinvestigated.Theoptimumconditionswereasfollows:themolarfractionofA1C13inionicliquid[x(AlCl3)]being0.67,molarratioofionicliquidtoanthracenebeing2:1,molarratioofoxalylchloridetoanthracenebeing2:1,reactiontemperaturebeing40℃andreactiontimebeing6h.Underaboveconditions,theyieldandselectivityof1,2-aceanthrylenedionecanreach91.5%and98.3%respectively.Furthermore,[Emim]C1-A1C13ionicliquid,comparedwithmetalhalidessuchasAlCl3,wasfoundtocatalyzethereactionasanovelenvironmentalfriendlycatalystandsolventandcanbereused.

  • 标签: 芳香烃 功能性大分子 酰基甘油 催化作用
  • 简介:Thisworkdealswiththekineticsofco-condensationpolymerizationofAB2andABmonomers,givingexpressionsofthetwo-dimensionalmolecularweightdistributionfunctionandthenumber/weightaveragemolecularweightsoftheresultingcopolymers.Thetwo-dimensionalmolecularweightdistributiondependsontwoindices,nandl,whicharetherespectivenumbersofAB2andABunitsinacopolymerspecies.Theevolutionofthetwo-dimensionalweightandzdistributionsduringtheco-condensationpolymerizationhasbeenevaluatedsystematically.Finally,thetwo-dimensionaldistributionwastransformedintoaone-dimensionalmolecularweightdistributionwithonlyonevariable(themolecularweightoftheproductsinsteadofthedegreeofpolymerization).Thecalculatedresultsshowthatthehighlybranchedcopolymerhasaverybroadmolecularweightdistributionwhentheco-condensationpolymerizationapproachescompletion.

  • 标签: 共聚物 动力学分析 分子量分布 浓缩 AB2树脂 AB树脂
  • 简介:Immobilizedtriazinedyeaffinitychromatographyhasbeenwidelyusedforproteinpurification.Inthispaper,CibacronBlueF3G-4wasimmobilized,throughaspacerarm,ontoarigidhydroplhilicporouspolymerbyreactinganepoxy-group-containingpoly(vinylalcohol)with6-aminohexyl-N'-CibacronBlueF3G-A,whichwasobtainedbyreactingCibacronBlueF3G-4withexcessof1,6-diaminohexane,inapH8.6buffer,Theepoxy-group-containingpoly(vinylalcohol)waspreparedbytreatingmacroporouspoly(vinylalcohol)withexcessepichlorohydrininthepresenceofNaOHindimethylsulfoxide.Themacroporouspoly(vinylalcohol)waspreparedbyhydrolysisofmacroporouscrosslinkedpoly(vinylacetate),whichwassynthesizedbysuspensioncopolymerizationofvinylacetateandtriallylisocyanurateinthepresenceofbutylacetateandn-heptaneasdiluents.TheCibacronBlueF3G-A-immobilizedpoly(vinylalcohol)waspackedinastainlesssteelcolumn(250×5mmI.D.)andthechromatographicbehaviorsofseveralproteins(cytochromec,lysozyme,bovineserumalbumin,insulin,andlactatedehydrogenase)weredetermined.

  • 标签: 蛋白 净化 色谱法