简介:Inthispaper,photoexcitationprocessesinthebilayerdevicesbasedoninorganicmaterialsandpoly(N-vinyl-carbazole)(PVK)wereinvestigated.Inordertoclarifytherolesofinorganicmaterialsinphotoconductivepropertiesofbilayerdevices,TiO2andZnSwerechosentocombinewithPVK.Amodelforgenerationofphotocurrent(Iph)insinglelayerdeviceofPVKwasobtained.Itisdeducedthattherecombinationrateconstant(Pcomb)andtheionizationrateconstant(γ)ofexcitonsshouldbeconsideredasthemostimportantfactorsforIph.Forinorganicmaterials(TiO2orZnS)/PVKbilayerdevices,inreversebiasof-4V,thephotocurrentof115mA/cm2intheTiO2/PVKdevicewasobserved,butthephotocurrentintheZnS/PVKdevicewasonly10mA/cm2undertheilluminationlightof340nmandthelightintensityof14.2mW/cm2.TheweakerphotocurrentisattributedtotheabsorptionofZnSwithinUVregionandtheenergyoffsetattheinterfacebetweenPVKandZnS,whichimpedesthetransportofchargecarriers.
简介:Arareearthcoordinationsystemwasfirstinvestigatedasanewtypeofcatalystforthering-openingpolymerizationofα-aminoacidN-carboxyanhydrides(NCAs).Theresultsforthepolymerizationofγ-stearyl-α,L-glutamate(SLG)NCAusingneodymiumacetylacetonate(Nd(acac)3)-orneodymiumtris(2-ethylhexylphosphonate)(Nd(P204)3)-triethylaluminum-waterascatalystswerecomparedwiththoseusingconventionalcatalysts.Itwasfoundthatthehelicalpoly(γ-stearyl-L-glutamate)withhighmolecularweightaswellasnarrowmolecularweightdistributioncanbeobtainedinthepresenceofNd(acac)3/AlEt3-1/2H2O.ThepolymerobtainedwascharacterizedbyIRandNMRspectroscopy.
简介:AStronglyhydrophilichydrogen-bondingadsorbent-macroporouscrosslinkedPoly(Nvinyl-acetamide),whichcontainbothhydrogenbondacceptoranddonator,wassynthesized.Adsorptionmechanismanddynamicadsorptionoftanninfromaqueoussolutionontotheadsorbentwereinvestigated.MostofthedifferntialadsorptionheatsforvariousadsorptioncapacitiescalculatedfromtheadsorptionisothermsaccordingtoClapeyron-Clausiusequationlayintherangeofhydrogenbondenergy(8-50J/mol).Adsorptionpropertiesoftheadsorbentwerestudiedindetail.Theseresultsrevealedahydrogenbondingmechanismoftheadsorptionoftanninfromaqueoussolutionontotheadsorbent.Theresultofthedynamicadsorptionoftanningwiththeinitialconcentrationunder600mg/Lshowedthattheadsorptionrateoftanninexceeded90%whentheflowratewas3BV/handtheeffluentvolumereached100BV.Therefore,thedevelopedhydrogen-bondingadsorbent-macroporouscrosslinkedpoly(N-vinyl-acetamide)-isanexcellentadsorbenttoremovetanninfromextractofnaturalproducts,andhasgreatvalueinapplication.
简介:glutamic酸(LG)和丁氨二酸酸(ASP)的随机的共聚物,poly(LG-co-ASP),能成功地与debenzylation经由N-carboxyanhydride戒指开始copolymerization的联合与设计作文被综合。-benzyl-L-glutamateN-carboxyanhydride(BLG-NCA)和-benzyl-LaspartateN-carboxyanhydride(BLA-NCA)的戒指开始copolymerizations被使用不同的胺包括执行象开始者的triethylamine(茶),diethylamine,n-hexylamine(NHA),triphenylamine,二苯胺或苯胺。所有6胺是高度有效的poly变得明确(BLG-co-BLA)共聚物与尽管聚合经由不同机制(正常的胺机制或/并且激活的单体机制)继续了,设计了作文,它基于胺的化学结构。分子的重量(BLG-co-BLA)poly,共聚物能被茶集中和聚合时间调停。然后,debenzylation(BLG-co-BLA)poly,共聚物被进行准备相应吸水的随机的共聚物(LG-co-ASP)poly以ASP结构的单位与子单元组织。LG结构的单位在的内容(LG-co-ASP)poly,共聚物在NCA单体BLG-NCA与那些匹配在NHA或茶开始并且接近了理论线的戒指洞copolymerizations喂。diblock共聚物(BLG-b-BLA)能被BLGNCA和BLA-NCA的顺序的增加也poly经由生活NCA戒指洞copolymerization综合。
简介:ThesorptionbehaviorofN-methyl-2-thio-imidazoleresin(MTIR)forRh(Ⅲ)wasinvestigated.TheoptmumsorptionconditionofMTIRforRh(Ⅲ),sorptionratet1/2=84min,sorptioncapacity1.37mmolRh(Ⅲ)/gMTIR,[140.5mgRh(Ⅲ)/gMTIR],sorptionmolarratio0.34Rh(Ⅲ)/functionalgroup,distributioncoefficientD=2.5×10^3mg·g^-1weredetermined.ThesorptionselectivityofMTIRforRh(Ⅲ)inthepresenceofcommonmetalions,Fe^3+,Co^2+,Ni^2+andCu^2+wasexamined.Rh(Ⅲ)adsorbedonMTIRcanbeelutedquantitativelybyusingamixedsolutioncomposedof20%thio-urea-acetone:6molHCl.dm^-3(1:1vol.)usedasaneluent.Rh(Ⅲ)canbeseparatedfromthemixtureofRh(Ⅲ)andFe^3+,Co^2+,Ni^2+,Cu^2+byusingD72resinandMTIRsuccessively.