大分子自組裝研究的進展江明課件

1、大分子自組裝研究的進展Studies on Macromolecular Self-assembly 江 明復旦大學高分子科學系分子組裝是最普遍的物理化學現(xiàn)象，是構建生命體系的基本途徑大分子自組裝是超分子化學和高分子科學的交叉領域Macromolecular self-assembly - interdisciplinary research field Important Part of Supramolecular Chemistry and polymer science 大分子自組裝是創(chuàng)造具有納米或亞微米尺度的結構新物質的簡單和清潔的途徑Simple and clean ways to

2、 create new , structured polymeric materials (soft matters) in nano or sub-micro sizes 美國科學雜志于2005年出版?？?，提出了21世紀亟待解決的25個重大科學問題，化學自組裝是其中唯一的化學問題。Robert F. Service Science 2005, 309, 95.Macromolecular Self-assembly :大分子自組裝的兩重含義：以大分子為組裝單元構建組裝體Macromolecules as building blocks to form structured assemblie

3、s以小分子為組裝單元構建超分子聚合物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年代末我國無系統(tǒng)性大分子自組裝研究先驅性的研究Pioneer work 90 年代初吉林大學 沈家驄, 張希等 氣/液界面“浮萍”與“倒浮萍”膜組裝微相分離間隔基效應兩親性聚合物 聚合物自組織層狀結構（有序性與穩(wěn)定性相結合）界面組裝 提出了類“浮萍”與“倒浮萍”聚合物超薄膜的模型，利用親、疏水力進行組裝，為解決聚合物膜的穩(wěn)定性與有序度相矛盾的問題提供了新思路。沈家驄、張希等Langmuir, 1994, 10, 2727Thin Solid Films, 1992, 21

6、0, 625Macromolecules, 1991, 24, 4986 Macromolecules, 1990, 23, 5158浮萍倒浮萍airwaterairwater系列學術研討會1991年沈家驄 H. Ringsdorf長春夏季化學研討會：有序功能體系國際香山科學討論會-1994年 超分子體系1998年 超分子體系:從分子構筑到功能組裝2001年超分子體系：材料科學與生命科學間的橋梁2004年超分子體系：從微米/納米結構研究材料科學和生物技術的方法 楊柏, 吉林大學張希, 清華大學高長有, 浙江大學Supramolecular Layered Structure Multi-lay

7、er membreneNano-pattering of surface Hollow micro-encapsulesUV Vis基于高分子膠束的層狀組裝：偶氮苯分子的包覆與光致異構化速率的提高 一般偶氮苯在固態(tài)膜中的光致異構化速率和效率常常比其在溶液中低。我們巧妙的利用高分子膠束結構所提供的微環(huán)境，使偶氮苯光致異構化的速率在固態(tài)膜中比其在溶液中還快一倍。 LbL 薄膜甲苯溶液張希 等 et al. Langmuir, 2006, 22, 39064.0710-3 9.0310-3 1.1410-2 復旦大學 Fudan UniversityMing Jiang （江明）Daoyong Ch

8、en （陳道勇）Ping Yao （姚萍）90年代初， 研究興趣在高分子氫鍵相互作用和相容性問題PS(OH)-X X 8mol% PMMAABsegment pairing interpolymer complex大分子絡合物驅動力：氫鍵自發(fā)過程分子組裝？Each A chain interacts with many B chains and vice versa 無規(guī)則的聚集體separated coils +common solvent我們反復思考的問題是：能否通過高分子間的絡合作用實現(xiàn)規(guī)則組裝？我們提出并成功地實現(xiàn)了 “高分子膠束化的非嵌段共聚物路線”“Block-copolymer-

9、free routes for polymeric micellization via interpolymer complexation ”Interaction groups將質子給體基限于鏈的端基上Restricting the reaction groups within certain positions along the chainOne of Approacheshydrogen bonding leads to graftcopolymers and then 非共價鍵合膠束(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多種途徑實現(xiàn)“非嵌段共聚物膠束化”均聚物，離聚物，齊聚物，接枝共聚物等均可用為組裝單元這是具有普遍意義的路線：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-殼“非共價”連接，通過殼交聯(lián)和核溶解獲得空心球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環(huán)境響應膠束：pH, 溫度，光，離子強度等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交聯(lián)PAApH increaseCore-crosslinked miclle Low crosslinking density is necessary !pH=1.3Stable micel

19、le交聯(lián)劑：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 環(huán)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環(huán)糊精 是研究的最多的作用主體在高分子方面主要是用于多聚輪烷-CD / PEO如何將環(huán)糊精的包結絡合用于構建高分子膠束？ 通過inclusion complexation 構建高分子膠束基

24、本思路： 合成分別帶CD和ADA的親水和疏水高分子， 在水中形成通過inclusion interaction 連接的核殼膠束（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 環(huán)糊精的包結絡合在大分子組裝研究中有很大的發(fā)展空間:表面活性劑; 納米金屬粒子; 光響應有機分子; 催化陳道勇等： 聚合反應/組裝同步法合成納米結構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 據(jù)2005 全年第二陳道勇， 江明 Account of Chemical Research , 38, 494, 2005Strategies for Constructing Polymeric Micelles and Hollow

29、 Spheres in Solution via SpecificIntermolecular Interactions新挑戰(zhàn)：從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已尋求到合適途徑獲得核殼納米微凝膠Mixing at pH 5.3, weak interaction Adjust pH 10.3, Lys aggregates, Oval Protection Heat denatured具有普遍意義的途徑Globular + Globular:Ovalbumin and LysozymeBovine Serum Albumin and LysozymeOvalbumin and OvertransferrinLinear + Globular:as-Casein + Overtransferrin(as,beta,kappa-)Casein + LysozymeGlobular pro