大分子自组装研究的进展

大分子自组装研究的进展StudiesonMacromolecularSelf-assembly江明复旦大学高分子科学系分子组装是最普遍的物理化学现象，是构建生命体系的基本途径大分子自组装是超分子化学和高分子科学的交叉领域Macromolecularself-assembly-interdisciplinaryresearchfieldImportantPartofSupramolecularChemistryandpolymerscience大分子自组装是创造具有纳米或亚微米尺度的结构新物质的简单和清洁的途径Simpleandcleanwaystocreatenew,structuredpolymericmaterials(softmatters)innanoorsub-microsizes美国科学杂志于2005年出版专刊，提出了21世纪亟待解决的25个重大科学问题，化学自组装是其中唯一的化学问题。RobertF.ServiceScience2005,309,95.MacromolecularSelf-assembly:大分子自组装的两重含义：以大分子为组装单元构建组装体Macromoleculesasbuildingblockstoformstructuredassemblies以小分子为组装单元构建超分子聚合物SmallmoleculesasbuildingblockstoformSupramolecularPolymersACiferri,MacromolecularRapidCommunications,2002,23,511ABNNOOOHO4OOHBuildingblocks:smallmoleculeswithproton-donatingandproton–acceptinggroupsNNOOOHO4OOHNNOHOABNOONOOORORNNNNNNButButButButHHHHNOONOOORORNNNNOOOOHHNOONOOORORNNNNNNButButButButHHHHNOONOOORORNNNNOOOOHHNNNNHHNNOONHButButSupramolecularPolymersALittleworkinChinaMacromoleculesasbuildingblockstoformstructuredassembliesMicellizationofblockcopolymersinselectivesolventsCovalentbondsconnectingthecoreandshellselectivesolventforredblockselectivesolventforblueblockCharacters:Size10-200nmAmphiphilicityApplications:EncapsulationDrug-delivery,Micro-reactor:Nano-metalparticles,Nano-semi-conductorparticlesCatalysis至80年代末我国无系统性大分子自组装研究先驱性的研究Pioneerwork90年代初吉林大学沈家骢,张希等气/液界面“浮萍”与“倒浮萍”膜组装微相分离间隔基效应两亲性聚合物聚合物自组织层状结构（有序性与稳定性相结合）界面组装提出了类“浮萍”与“倒浮萍”聚合物超薄膜的模型，利用亲、疏水力进行组装，为解决聚合物膜的稳定性与有序度相矛盾的问题提供了新思路。沈家骢、张希等Langmuir,1994,10,2727ThinSolidFilms,1992,210,625Macromolecules,1991,24,4986Macromolecules,1990,23,5158浮萍倒浮萍airwaterairwater系列学术研讨会1991年沈家骢H.Ringsdorf长春夏季化学研讨会：有序功能体系国际香山科学讨论会-1994年超分子体系1998年超分子体系:从分子构筑到功能组装2001年超分子体系：材料科学与生命科学间的桥梁2004年超分子体系：从微米/纳米结构研究材料科学和生物技术的方法杨柏,吉林大学张希,清华大学高长有,浙江大学SupramolecularLayeredStructureMulti-layermembreneNano-patteringofsurfaceHollowmicro-encapsulesNNNNUVVis01234567801234ln(A0-Aeq)/(At-Aeq)Time(min)01234560.070.090.110.130.15Absat320nmNumberofcycles基于高分子胶束的层状组装：偶氮苯分子的包覆与光致异构化速率的提高一般偶氮苯在固态膜中的光致异构化速率和效率常常比其在溶液中低。我们巧妙的利用高分子胶束结构所提供的微环境，使偶氮苯光致异构化的速率在固态膜中比其在溶液中还快一倍。LbL薄膜甲苯溶液张希等etal.Langmuir,2006,22,39064.07×10-39.03×10-31.14×10-2复旦大学FudanUniversityMingJiang（江明）DaoyongChen（陈道勇）PingYao（姚萍）90年代初，研究兴趣在高分子氢键相互作用和相容性问题CCF3F3COHCHCH2CHCH2nmCH2CO=COCH3CH3nPS(OH)-XX8mol%PMMAABsegmentpairinginterpolymercomplex•大分子络合物•驱动力：氢键•自发过程•分子组装？？EachAchaininteractswithmanyBchainsandviceversa无规则的聚集体separatedcoils+commonsolvent我们反复思考的问题是：能否通过高分子间的络合作用实现‘规则组装’？我们提出并成功地实现了“高分子胶束化的非嵌段共聚物路线”“Block-copolymer-freeroutesforpolymericmicellizationviainterpolymercomplexation”Interactiongroups将质子给体基限于链的端基上RestrictingthereactiongroupswithincertainpositionsalongthechainOneofApproacheshydrogenbondingleadsto‘graft’copolymersandthen非共价键合胶束(NCCM)ProtondonorendsProtonacceptorNCCMIn‘obverse’and‘reverse’NCCMofCPB/PVPyPVPyCPBInchloroformObverseNCCMReverseNCCMNpolybutadienewithcarboxylgroupsatends1001011021030123f(Dh)Dh(nm)PVPy-(CPB)(PVPy)-CPBHydrodynamicDiameter(Dh)Distribution多种途径实现“非嵌段共聚物胶束化”均聚物，离聚物，齐聚物，接枝共聚物等均可用为组装单元这是具有普遍意义的路线：Polyimide/PVPy-containingpolymersJACS,123,12097,2001;JPhysChemB,108,550,2004;108,5225,2004Carboxyl-endpolybutadiene(CPB)/Poly(vinylalcohol)(PVA)-Macromolecules,37,1537,2004Poly(carprolactone)(PCL)/Poly(acrylicAcid))(PAA),Langmuir21,1531,2005Poly(styrene-co-MAA)/Poly(vinlpyrollidone)Langmuir,17,6122,2001PCL/PMAA-g-PCLAngewChemIntlEdi,41,2950,2002利用核-壳“非共价”连接，通过壳交联和核溶解获得空心球Greatinterestinobtainingpolymerichollowspheres:LiuG,WooleyKdegradablecrosslinkableblockcopolymerselectivesolventcrosslinkingphoto-degradationchemical-degradationFromNCCMtoHollowSpherescrosslnkingPVPyshellby1,4–dibromobutaneinCH3NO2CavitationinDMFCH3NO2PS(OH)PVPyDMFTEMImageofHollowSphereobtainedbycoredissolutionfromNCCMof(PCL)-PAA环境响应胶束：pH,温度，光，离子强度等HydroethylCellulose(HEC)–g–Poly(AcrylicAcid)HEC-g-PAASelf-assemblyof‘DoubleHydrophilic’GraftCopolymerDouHJ,JiangMetal.AngewChemIntlEd42,1516,2003Ce(Ⅳ)/H+HEC-g-PAAPreparationofgraftcoplymer接枝共聚物分子量的表征CharacteristicdataofHEC-g-PAAcopolymersSampleNo.AA:AGUa(molarradio)Mη×10-5(HECbackbone)Mη×10-5b(PAAgrafts)AveragegraftpointFeedcompositionPolymercompositionCAA-00.23:10.25:10.9CAA-11.17:11.28:10.90.1751.58CAA-23.50:12.54:10.90.2102.61Cellulase+PAAgraftsAGUTable2-2LLSCharacteristicdataofCAA-1andCAA-2SampleNo.Mw×10-5a(HEC-g-PAA)Dhb/nmRg/nmRg/RhCAA-11.6753.8401.49CAA-23.3375.659.61.58Rg/Rh=1.50MeansrandomcoilRadiusofGyrationRgHydrodynamicRadiusRh02468101214100200300400500Dh/nmpHCAA-2CAA-1ThesolutionatpHrangeof2-3wasunstable:theapparentDhincreasedwithtime.TheDhvaluesmeasured20minafterthesolutionpreparationwereused.Figure3-2DhofHEC-g-PAAcopolymersasafunctionofpH.Theconcentrationwas1mg/ml.ⅢⅡⅠHEC-g-PAAMicellespH3,molecularlydissolvedpH3,micellesformedpHdecreasepHinducedmicellizationMicelle(pH3)-COOHofPAAatpH3cancomplexwithHECandformthe“core”ofmicellesUncomplexedHECsegmentsformthe“shell”ofmicelles(pH3)pH3,molecularlydissolvedAtlowpH,PAAprotonated,formingcomplexwithHECmainchain–core;HECwithoutPAAbranchesformedshellpH-controlledcomplex