简介:Poly(methylmetacrylate)(PMMA)/Y0.0025Si0.025Ba0.9725(Ti(0.9)Sn0.1)O3(YBTS)composites在YBTS的不同重量比率被准备(0wt%,5wt%,10wt%和20wt%YBTS)招待以便在PMMA的电、光的性质上调查YBTS增加的效果。电的性质(阻抗,绝缘的经常的绝缘的损失和交流电导率)在频率范围被学习10kHz-1MHz并且在温度范围20鈥?0掳C。在增加YBTS的内容之上陶器,我们在在绝缘的经常的、绝缘的损失和PMMA的交流电导率的阻抗和增加观察了减小主人。我们也发现在高YBTS内容的松驰过程由于在离子的传导性的松驰。吸收系数(伪)在波长范围被决定了230鈥?在为所有YBTS-PMMAcomposites的房间温度的00nm。而且,YBTS的增加陶器高度特别在300nm下面提高PMMA主人的紫外吸收。对PMMA主人陶器的20wt%YBTS的增加减少从5eV的光精力差距到3.41eV。关联在之间电,光并且SEM结果被报导。关键词电-光-PMMA,陶器-铁电体-Composites
简介:TheSolvatedMetalAtomImpregnation(SMAI)techniquewasemployedtopreparemacroporousresinimmobilizedPd-Cubimetallicclustercatalysts.TheX-raydiffraction(XRD)andtransmissionelectronmicrograph(TEM)showedthatPd-CualloywasformedandtheparticlesizesofPd-Cuclusterswereverysmall,withaveragediameters<3nm.X-rayphotoelectronspectroscopyindicatedthatbothPdandCuwereinzero-valentstate.ThecatalyticactivitiesofthemacroporousresinimmobilizedPd-Cucatalystsinhydrogenationof4-methyl-3-penten-2-oneweremuchgreaterthanthatofthecarbonsupportedPd-Cucatalysts.
简介:Fourpolymer-supportedFe-Cotetrametallicclustershavebeenpreparedbyionexchangeandligandexchange.TheirstructureswerecharacterizedbyIR,UV/visiblediffusereflectancespectraandelementalanalysis,andbyanalogywiththereferenceclusterPhCH2NMe3FeCo3(CO)2.Thefourheterogenousclusterswereefficientcatalystsinthehydroformylationof1-hexene,turnovernumbersamountedto823—924withtheyieldof83.2—92.4%heptylaldehydesandratiosofnormalaldehydetoiso-aldehydeof1.2—1.6,theyarefacilitatedformingthenormalaldehydeincomparisonwiththehomogeneousanalogue.Forthepolymer-supportedclusterspreparedbyionexchange,thepolymer-cationpartshadnoobviouseffectontheactivityoftheclusteranion.Thepolymer-phosphinesubstitutedclusterpreparedbyligandexchangewasmorestablethantheclusterspreparedbyionexchange.
简介:Alginate-Cu(Ⅱ)complexbeadsormembraneswerepreparedforremovalofurea.ThemechanismofsorptionofureawasidentifiedbyUV-Visiblespectra,FT-IRspectraandFar-Infraredspectra.Thefactorsaffectingtheureasorptioncapacitywerediscussedindetail.ResultsshowedthattheAlginate-Cu(Ⅱ)complexsorbentcansorbabout60myureapergramofsorbentat37℃andtheconcentrationofureawas130mg/100mlinNa2HPO4andNaH2PO4buffersolution(pH=7.0).
简介:Anovelpolymercontainingthesucrosegroupwassynthesizedbyradicalpolymerizationfromanenzymaticallypreparedmonomer,1′-O-vinyladipoyl-sucrose(VAS).TransesterificationreactionofsucrosewithdivinyladipateinanhydrouspyridinecatalyzedbyanalkalineproteasefromBacillussubtilisat60℃for7daysgaveVAS(yield55%)withoutanyblocking/deblockingsteps.ThevinylsucroseestercouldbepolymerizedwithpotassiumpersulfateandH2O2asinitiatortogivepoly(1′-O-vinyladipoyl-sucrose)withMn=33,000andMw=53,200,Mw/Mn=1.61.Thepolymerwasbiodegradable.After6daysinaqueousbuffer(pH7),thisalkalineproteasecoulddegradepoly(1′-O-vinyladipoyl-sucrose)toMnofca.1080,Mw/Mn=3.30(37℃),andMnofca.5200,Mw/Mn=2.44(4℃).Thepolymercontainingthesucrosebranchwouldbeafunctionalmaterialinvariousapplicationfields.
简介:EscherichiacoliL-asparaginasewasmodifiedwithO-car-boxymethylatedchitosanusingglutaraldehydeasacouplingagent.Theresultingcoujugateretainedmorethan50%ofitsoriginalenzymeactivityundertheprotectionofitsnormalsubstrateorproductandshowedmarkedresistancetoproteolysisbytrypsinandchymotrypsin.
简介:Conventionalchloromethylation,paraformaldehyde/hydrogenchlorideinaceticacidmedium,wasappliedto1,2-dimethoxybenzene.Chloroform-solublepoly(3,4-dimethoxy-o-tolylene)wasobtainedwithanintrinsicviscosityof0.034dLg~(-1).ThepolymerwasevaluatedasacondensationredoxpolymerprecursorformedbyaFriedel-Craftsreaction.Cleavageofthemethoxygroupspresentinthispolymerresultedinpoly(3,4-dihydroxy-o-tolylene)whichmanifestedagreatair-oxidationresistance.Theredoxpropertyofthelatterpolymerwasfoundtobe1017mVbypotentiometrictitrationwith0.05Ncericammoniumnitrateat25℃.Thismidpotentialwascomparedtothatofcatechol,amonomericanalogue,underthesametitrationconditions.
简介:CrosslinkedN,O-carboxymethylchitosanresinswhichcanselectivelyadsorbtriglyceride,werepreparedbythereactionofN,O-carboxymethylchitosanwithglutaraldehydesolution.Adsorptionexperimentswereperformedbyaddingtheresinstotheserum.Theresultsshowedthatthistypeofadsoirbentcouldcutdowntheconcentrationoftriglycerideinserumby56.4%(3.35mg/gresin)atmost,whileconcentrationofthetotalprotein(TP)decreasedonlyby10.9%atleast,sothisnoveladsorbentcanbeusedtocurehypertriglyceridemiabyhemoperfusioninthefuture.
简介:CuO/γ-Al2O3catalystswerepreparedbyplasmatreatmentandconventionalimpregnationmethods.Thecatalyticcombustionoftwokindsofvolatileorganiccompounds(VOCs),tolueneandbenzene,werecarriedoutovertheseCuO/γ-Al2O3catalysts.ThesurfacepropertiesofthesecatalystswerecharacterizedbyX-rayDiffraction(XRD)andScanningElectronMicroscopy(SEM).TheexperimentalresultsshowedthatincatalyticcombustiontheactivityoftheCuO/γ-Al2O3catalystpreparedviaplasmawasmuchhigherthanthatoftheCuO/γ-Al2O3catalystpreparedbyconventionalimpregnationmethod.XRDresultsshowedthatanenhanceddispersionhadbeenachievedwiththeplasmatreatment.SEMresultsindicatedthatthesizebecamemuchsmallerandthesurfacebecamemoreuniformwiththeplasmatreatment.
简介:Metalion-imprintedlycrosslinkedchitosanresin1andresin2werepreparedbytheuseofCu^2+andNi^2+astemplateionsandglutaraldehydeascrosslinkingagent,respectively,ThroughinvestigationontheadsorptioncapactiesandbindingconstantsforCu^2+,Ni^2+andCo^2+ionsonchitosanresins,resin1andresin2exhibittheadsorptionselectivityforthemixturesolutionof1L1Cu^2+andNi^2+ions.Theadsorptionselectivityofmetalion-imprintedresinsfortheirtemplateionsinmuchhigherthanthatofuncrosslinkedchitosanresin.
简介:Gasphasereductionofcarbonmonoxidetoformaldehydeandethylenewasfoundinelectrochemicalcellwithaninorganicionexchangerα-Zr(HPO4)2·H2Ousedassolidproton-conductingelectrolyteatroomtemperatureandatmosphericpressure.ThetypeandamountoftheelectroreductionofCOdependonthedifferentmetalelectrodesandcurrentdensities,whichgivesalankbetweenheterogeneouscatalysisandelectrochemistry.