学科分类
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9 个结果
  • 简介:TheA-Bblockcopolymerof0634-chloroethylglycidyletherwithstyrenecanbegotbytheeasymethodofone-steppolymerization.ThestructureofA-Bblockcopolymerwasconfirmedbytheelementaryanalysis,turbiditytitration,molecularweightmeasurement,IR-spectra,13C-NMR,1H-NMRandDTAinvestigationoftheproducts.Also,theeffectsofsolvents,reactiontimeandtemperatureonthecomposition,Mnandyieldofcopolymerhavebeenstudied.

  • 标签: 共聚物 苯乙烯 苯乙烯共聚物
  • 简介:Averymildandextremelyefficienthydrolysismethodfortransformationofpolystyrene-b-poly(tert-butylacrylate)(PS-b-PtBA)topolystyrene-b-poly(acrylicacid)(PS-b-PAA)wasdesignedandcarriedoutusingmoreconvenientandinexpensivechlorotrimethylsilane/sodiumiodideasreagents.Thehydrolysisproductcanself-assembleinaqueousmediatogiveregularmicelleswithPSblockformingthecoreandPAL4blockformingthecorona,orintetrahydrofuran(THF)togivereversemicelleswiththehydrophilicblockinthecore.

  • 标签: 共聚物 聚苯乙烯 丙烯酸盐 聚合反应
  • 简介:Inthiswork,DSCandSEMstudiesindicatethation-ligandinteractioncanbeutilizedtoenhancetheinteractionofpoly(styrene-block-2-vinylpyridine)[P(S-b-2VP)]andpolyethylenebasedionomer(Surlyn).Thecompatibilityforthisblendingsystemcanbeimprovedbythisspecialinteractionand20/80wtistheoptimumblendingcompositionwithgoodcompatibility.FTIRresultsfurthercertifythatstronginteractionsexistintheblendingsystem.

  • 标签: 聚(苯乙烯-B-2-乙烯基嘧啶) 相容性 离子交联聚合物 离子配位键交互作用.
  • 简介:Thehybridstructuresofpolystyrene-b-poly(ethyleneoxide)(PS-b-PEO)blockcopolymerandinorganicnanoparticleswithgoodstabilityandbiocompatibilityhavepotentialapplicationsindrugdeliveryandbioimaging.Sphericalco-assembliesofPS120-b-PEO318andoleylamine-cappedCdSquantumdots(QDs)areproducedsuccessfullyinthisworkbyaddingwatertoamixedcommonsolvent,suchasN,N-dimethylmethanamide(DMF)/chloroform,DMF/tetrahydrofuran(THF),orDMF/toluene.TheenergydispersiveX-ray(EDX)spectrumindicatesthatQDsarelocatedattheinterfacebetweenthecoreandshellofthesphericalco-assemblies.Theco-assemblyprocessduringwateradditionistracedbytransmissionelectronmicroscopy(TEM)andturbiditymeasurement.Sphericalco-assembliesareformedthroughbuddingfrombilayersoftheblockcopolymerandQDs.Themorphologyoftheco-assembliesisrelatedtothemiscibilityoftheQD-dispersingsolventswithwaterandthemorphologychangesfromasphericaltoavesicle-likestructurewithDMF/toluene.IncreasingTHFcontentinthemixedsolventcausesmorphologicaltransitionsfromsphericalco-assembliestomulti-branchedcylindersandmicelleswhereQDsarelocatedinthecentralcore.Increasingchloroformcontentyieldsvesicle-likestructureswithprotrudingrodsonthesurface.Themechanismofthemorphologicaltransitionsisalsodiscussedindetail.

  • 标签: Co-assembly Mixed common solvent PS-B-PEO Solvent composition
  • 简介:指向nano探查基于的一个可被细菌破坏的肿瘤poly(?-caprolactone)-b-poly(ethylene乙二醇)有磁性的回声成像(MRI)的块共聚物(PCL-b-PEG)micellefunctionalized对比代理人diethylenetriaminepentaacetic酸金轧(DTPA-Gd3+)在壳上并且一在红外线附近(NIR)在为磁性的回声和光双形式的成像的核心的染料是准备。纵的relaxivity(r1)PCL-b-PEGDTPA-Gd3+,micelle是13.4(mmol/L)?1s?1,DTPA-Gd3+的三褶层,并且比有类似的结构的许多聚合对比代理人的高。在里面忍受xenografted胸肿瘤的一只裸体老鼠的光成像显示出的vivo双形式的micelle优先地经由folic在肿瘤积累了由提高的渗透和保留(EPR)效果的调停酸的活跃指向和被动累积。结果显示dualmodalitymicelle是为癌症察觉和诊断的有希望的nano探查。

  • 标签: 磁共振成像 乳腺肿瘤 PCL 双模式 PEG 胶束
  • 简介:Lamellarcrystalsofdiblock,triblockandfour-armpoly(ethyleneglycol)-b-poly(ε-caprolactone)(PEG-b-PCL)crystalline-crystallinecopolymersweresuccessfullyobtainedfromtheirsolution.Morphologyandstructureoflamellarcrystalsofcrystalline-crystallinecopolymerswereinvestigatedusingtapping-modeatomicforcemicroscopy(AFM)andselectedareaelectrondiffraction(SAED).Allofthesesamplesshowedthetruncated-lozengemultilayerbasalshapeswithcentralscrewdislocationorcentralstack,whichwereallobtainedsimultaneouslyfromtheoilbath.ThediffractionpatternofPEGblocklamellarcrystalisattributedtothe(120)diffractingplanesandthepatternofPCLblocklamellarcrystalisattributedtothe(110)diffractingplanesand(200)diffractingplanesaccordingtotheSAEDresults.Four(110)crystalgrowthplanesandtwo(200)crystalgrowthplanesarediscoveredforthePCLblocks,butthe(120)crystalgrowthplanesofPEGblocksarehidedinthefigureofAFM.Thecrystallinestructureofthefour-armcopolymers(FA)ismoredisorderandconfusedthanthatofthediblock(DI)copolymerandthestriatedfoldsurfacestructuresoflamellarcrystalsoffour-armcopolymers(FA)aresmootherthantheseoflinearanalogues,owingtotheconfusedcrystallizationofblockscausedbythemutualrestrictionofblocksandthehindranceofthedendriticcores.Inaddition,theaspectratioofFAisgreaterthanthatoftheothers.Itishypothesizedthattherearetworeasonsforthechangeofaspectratios.First,the(200)diffractingplanesofPCLcrystalsgrewslowlycomparedtotheir(110)diffractingplanesbecauseofdifferenceintheenergybarrier.Secondly,edgedislocationsonthe(200)diffractingplanesarealsoresponsibleforthevariationoftheaspectratio.Consequently,thecrystallinedefectsareaugmentedbythecompetingblockscrystallizedsimultaneouslyandthehindranceofthedendriticcores.

  • 标签: 嵌段共聚物 结晶行为 Ε-己内酯 乙二醇 线性 溶液