大分子自组装研究的进展江明课件

1、大分子自组装研究的进展Studies on Macromolecular Self-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Macromolecular self-assembly - interdisciplinary research field Important Part of Supramolecular Chemistry and polymer science 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Simple and clean ways to

2、 create new , structured polymeric materials (soft matters) in nano or sub-micro sizes 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。Robert F. Service Science 2005, 309, 95.Macromolecular Self-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Macromolecules as building blocks to form structured assemblie

3、s以小分子为组装单元构建超分子聚合物Small molecules as building blocks to form Supramolecular Polymers A Ciferri, Macromolecular Rapid Communications, 2002, 23, 511ABBuilding blocks : small molecules with proton-donating and proton accepting groups ABSupramolecular PolymersA Little work in China Macromolecules as bui

4、lding blocks to form structured assemblies Micellization of block copolymers in selective solvents Covalent bonds connecting the core and shellselective solvent for red blockselective solvent for blue blockCharacters:Size 10-200nmAmphiphilicity Applications:Encapsulation Drug-delivery,Micro-reactor:

5、Nano-metal particles,Nano-semi-conductor particlesCatalysis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Pioneer work 90 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, 2727Thin Solid Films, 1992, 21

6、0, 625Macromolecules, 1991, 24, 4986 Macromolecules, 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Supramolecular Layered Structure Multi-lay

7、er membreneNano-pattering of surface Hollow micro-encapsulesUV Vis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 et al. Langmuir, 2006, 22, 39064.0710-3 9.0310-3 1.1410-2 复旦大学 Fudan UniversityMing Jiang （江明）Daoyong Ch

8、en （陈道勇）Ping Yao （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PS(OH)-X X 8mol% PMMAABsegment pairing interpolymer complex大分子络合物驱动力：氢键自发过程分子组装？Each A chain interacts with many B chains and vice versa 无规则的聚集体separated coils +common solvent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-

9、free routes for polymeric micellization via interpolymer complexation ”Interaction groups将质子给体基限于链的端基上Restricting the reaction groups within certain positions along the chainOne of Approacheshydrogen bonding leads to graftcopolymers and then 非共价键合胶束(NCCM)Proton donor endsProton acceptorNCCMInobverse

10、 and reverse NCCM of CPB/ PVPyPVPyCPBnitromethaneIn chloroformObverse NCCMReverse NCCMhexanepolybutadiene with carboxyl groups at endsPVPy-(CPB)(PVPy)-CPBHydrodynamic Diameter (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-containing polymersJACS ,123, 12097

11、, 2001; J Phys Chem B, 108, 550, 2004; 108, 5225, 2004Carboxyl-end polybutadiene (CPB) / Poly(vinyl alcohol)(PVA) - Macromolecules ,37, 1537, 2004Poly(carprolactone)(PCL) / Poly(acrylic Acid) (PAA) , Langmuir 21, 1531 , 2005Poly(styrene-co-MAA) / Poly(vinlpyrollidone)Langmuir ,17,6122, 2001PCL/ PMAA

12、-g-PCLAngew Chem Intl Edi, 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Great interest in obtainingpolymeric hollow spheres:Liu G, Wooley Kdegradablecrosslinkableblock copolymerselective solventcrosslinkingphoto-degradationchemical-degradationFrom NCCM to Hollow Spheres crosslnking PVPy shell by 1,4 dib

13、romobutane in CH3NO2Cavitation in DMF CH3NO2PS(OH)PVPyDMFTEM Image of Hollow Sphere obtained by core dissolution from NCCM of (PCL)-PAA环境响应胶束：pH, 温度，光，离子强度等Hydroethyl Cellulose (HEC) g Poly(Acrylic Acid) HEC-g-PAASelf-assembly of Double Hydrophilic Graft CopolymerDou HJ, Jiang M et al. Angew Chem In

14、tl Ed 42, 1516, 2003Ce()/H+HEC-g-PAAPreparation of graft coplymer接枝共聚物分子量的表征Characteristic data of HEC-g-PAA copolymersSample No.AA:AGU a (molar radio)M10-5(HEC backbone)M10-5 b(PAA grafts)Averagegraft pointFeed compositionPolymer compositionCAA-00.23:10.25:10.9CAA-11.17:11.28:10.90.1751.58CAA-23.50

15、:12.54:10.90.2102.61Cellulase+PAA graftsAGUTable 2-2 LLS Characteristic data of CAA-1 and CAA-2Sample No.Mw10-5 a(HEC-g-PAA)b/ nm/ nm/CAA-11.6753.8401.49CAA-23.3375.659.61.58/=1.50Means random coilRadius of Gyration RgHydrodynamic Radius RhThe solution at pH range of 2-3 was unstable: the apparent i

16、ncreased with time. The values measured 20 min after the solution preparation were used. Figure 3-2 of HEC-g-PAA copolymers as a function of pH. The concentration was 1mg/ml. pH 3, molecularly dissolvedpH3)-COOH of PAA at pH3 can complex with HEC and form the “core” of micellesUncomplexed HEC segmen

17、ts form the “shell” of micelles (pH 3, molecularly dissolvedAt low pH, PAA protonated, forming complex with HEC main chain core; HEC without PAA branches formed shell pH-controlled complexation-induced micellization (low grafting density is necessary!)COOH COO- + H+pH pH At low pH, Crosslinking of P

18、AA grafts - to lock the structureDialysis against water, pH 3 7: DLS: size 350nm 650nmTEM: micelles hollow spheresAt pH 7, Hollow Spheres Form! pH 3-7:pH-dependent micelle-hollow- sphere transition pH1.3交联PAApH increaseCore-crosslinked miclle Low crosslinking density is necessary !pH=1.3Stable micel

19、le交联剂：2,2-(ethylenedioxy)bis(ethylamine) Dialysis pH=7PAA+HECdecomplexationReversible ?pH 3, protonation,complexation pH7, deprotonation, de-complexation, disintergaration Reversibility of the transition pH 3-7:pH-dependent micelle-hollow- sphere transition TEM observations（CAA2）pH=1.3pH induced mic

20、ellespH=7Hollow spherespH=1.3pH-induced micelles after one pH cycle PNIPAM (Polyisopropyl acrylamide) -based reversible thermo-sensitivityAdv Funct Mat 15, 695 (2005)PAA-based pH 4.5 8.5, volume increases by 130 timesLangmuir 21, 1531 (2005)Building block : linear polymersArchitectural effect ?Dendr

21、imer and Dendron as building blocks Preparation of Dendron G3H-Bonding Dendronized Polymers Formation of nanoparticles from G3/PVP in common solvent , ultrasonic treatment Hollow spheres? Collapsed thin-layer hollow spheres ?Crosslinked hollow spheres - much high strength G3/PVP23Thick wall hollow s

22、pheres Self-assembly driven by H-BondingOther driving forces? Inclusion complexation ?- CD- CD- CDNo. of glucose units 678cavity diameter, 5.3 8.3height of torus, 7.9 diameter of outher periphery, 14.615.4 17.5 approx volume of cavity, 3174 262 427 环糊精cyclodextrin 7 hydrophilicityhydrophobicityStruc

23、tures and properties of Adamantane (ADA)d 7 7 V 180 3 262 3Adamantane Complex stable constant 105The -CD cavity apparently has the optimum dimensions for interaction with adamantane derivate.7 Adamantane CD环糊精 是研究的最多的作用主体在高分子方面主要是用于多聚轮烷-CD / PEO如何将环糊精的包结络合用于构建高分子胶束？ 通过inclusion complexation 构建高分子胶束基

24、本思路： 合成分别带CD和ADA的亲水和疏水高分子， 在水中形成通过inclusion interaction 连接的核壳胶束（NCCM） ATRPMn =1.67 x 104Mw/Mn =1.21Mn =1.87 x 104Mw/Mn =1.28CD-containing monomer GMA-CDPGMA-CD MW 10,400Characters:Double-scale hydrophobic regions : 100nm and 0.7nmCavities available for surface modification NH2-COOHnegatively charged

25、positively chargedMicelle surface modification Hollow sphere of crosslinked PGMA-CDDouble Scale Cavities 环糊精的包结络合在大分子组装研究中有很大的发展空间:表面活性剂; 纳米金属粒子; 光响应有机分子; 催化陈道勇等： 聚合反应/组装同步法合成纳米结构Macromolecules 2005, 38 , 3550 Most-Accessed Articles: 20051.Nanoporous Polystyrene Containing Hydrophilic Pores from an

26、ABC Triblock Copolymer PrecursorRzayev, J.; Hillmyer, M. A.Macromolecules 2005, 38(1), pp 3-5. 2.A One-Pot Approach to the Preparation of Organic Core-Shell Nanoobjects with Different MorphologiesPeng, H.; Chen, D.; Jiang, M.Macromolecules 2005, 38(9), pp 3550-3553. 3.Synthesis and Direct Visualizat

27、ion of Block Copolymers Composed of Different Macromolecular ArchitecturesPyun, J.; Tang, C.; Kowalewski, T.; Frechet, J. M. J.; Hawker, C. J.Macromolecules 2005, 38(7), pp 2674-2685. 4.Deep-Red Electroluminescent Polymers: 4.Synthesis and Characterization of New Low-Band-Gap Conjugated Copolymers f

28、or Light-Emitting Diodes and Photovoltaic DevicesYang, R.; Tian, R.; Yan, J.; Zhang, Y.; Yang, J.; Hou, Q.; Yang, W.; Zhang, C.; Cao, Y.Macromolecules 2005, 38(2), pp 244-253. 2005 据2005 全年第二陈道勇， 江明 Account of Chemical Research , 38, 494, 2005Strategies for Constructing Polymeric Micelles and Hollow

29、 Spheres in Solution via SpecificIntermolecular Interactions新挑战：从合成高分子到天然大分子Target Materials : Micelles or Nano core-shell hydrogel made of proteins and polysacchrids biocompatible, biodegradable, non-toxic and even eatable （可食用性）Ping Yao (姚萍）， Fudan UniversityOvalbumin(白蛋白） and Lysozyme（溶菌酶）Ovalbum

30、in: 385 aa, Mw 47000 DaIsoelectric Point 4.7, 7 nm 4.5 nm 5 nmLysozyme: 129 aa, Mw 14351 Da Isoelectric Point 10.7, 3.8 nm 2.4 nm 2.2 nm5.34.710.7已寻求到合适途径获得核壳纳米微凝胶Mixing at pH 5.3, weak interaction Adjust pH 10.3, Lys aggregates, Oval Protection Heat denatured具有普遍意义的途径Globular + Globular:Ovalbumin and LysozymeBovine Serum Albumin and LysozymeOvalbumin and OvertransferrinLinear + Globular:as-Casein + Overtransferrin(as,beta,kappa-)Casein + LysozymeGlobular pro