简介：Threenewpolysesquisiloxane-boundplatinumcomplexesweresynthesizedviahydrolysisofN,N-di(β-ethylmercaptoethyl)γ-(triethoxysilyl)propylamineorcohydrolysisofthemonomerwithdodecyltriethoxysilaneorwithphenylpropylthiethoxysilaneandimmobilixationonfumedsilica,followedbyreactingwithpotassiumplatiniteinacetoneunderargonatmosphere.Theplatinumcomplexesexhibitedhighcatalyticactivityforthehydrosilylationofolefinsbytriethoxysilane.Theeffectsoftemperatureandtheamountofcomplexonthecatalyticactivity,aswellastherecoveryandreusabilityofthecatalystswereinvestigated.

简介：Anewdi-functionadsorbent(JN-3)waspreparedbysulfhydrylmodified.ComparingwithAmberliteXAD-4andNDA-150,theequilibriumadsorptionforphenolontheJN-3fromaqueoussolutionswastested,perfectadsorptioncapacitywasshown.Pb2+canbealsoremovedbyJN-3becauseofthechelateinteractionbetweensulfhydrylgroupsandmetalions.Thisadsorbentcouldbeusedinremovalofcombinepollutantssuchasphenoliccompoundsandheavymetalionsfromwastestreams.

简介：Thechaindynamicsofapairofdiblockpoly(styrene-b-butadiene)(PS210-b-PB960)andtriblockpoly(styrene-b-butadiene-b-styrene)(PS200-b-PB1815-b-PS200)copolymersinbothdiluteandsemidilutetoluenesolutionshasbeencomparativelystudiedbydynamiclaserlightscattering.Asexpected,themutualdiffusionofindividualchainchangesintoafastcooperativediffusionofthechainsegments('blobs')betweentwoneighboringentanglementpointsforboththecopolymersasthesolutionchangesfromdilutetosemidilute.Furtherincreasesoftheconcentrationleadtoasecondslowrelaxationmode.Forthetriblockchains,thereexistsanadditionalmiddlerelaxationbetweenthefastandtheslowmodes.with0.33＜α＜0.44,muchsmallerthan0.75predictedor0.72observedforlinearhomopolymerchainsingoodsolvent.ItimpliesthatthesolventqualityoftolueneforPBmightnotbeasgoodasthatforPS.Duetosuchadifferenceinsolubility,itisreasonabletospeculatethatthePBandPSblocksaretransientlysegregatedinsemidilutesolution.TherelaxationofthesetransientPBandPSricherdomainsleadstotheobservedslowrelaxation.Suchaspeculationissupportedbytheappearanceofanadditionalslowrelaxationmodeinthestudyofpolyisoprene-b-polystyrene-b-polyisopreneinsemidilutesolutionincyclohexane,anon-selectivesolvent,inwhichwealternatedthesolubilitydifferencebyavariationofthesolutiontemperature.

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