【作者】 张彦峰；

【导师】 刘世勇；

【作者基本信息】 中国科学技术大学 ， 高分子化学与物理， 2010， 博士

【摘要】 通过非共价键相互作用自发进行的大分子超分子自组装体系以及基于聚合的杂化纳米材料和传感器对材料科学、生命科学、信息科学以及纳米科学与技术等众多的科学领域的发展都产生了重大的影响,已经成为21世纪最重要的科学问题之一。本论文集中研究环境响应性聚合物的控制合成、组装体的构筑和结构调控和无机/合物杂化纳米材料。在论文的前半部分,基于环境敏感水溶性高分子设计合成了一系列三杂臂星型聚合物。在水溶液中,研究了多种环境响应性三杂臂星型聚合物聚合物的超分子组装以及不同环境条件对超分子组装体的影响。论文的后半部分,主要研究无机/合物杂化纳米材料的制备。具体来说,本论文的工作包括以下几个方面：1.结合原子转移自由基聚合(ATRP)、开环聚合(ROP)和点击化学(Click Chemistry)技术制备了结构规整的两亲性温度敏感ABC三杂臂星型聚合物聚苯乙烯-聚(ε-己内酯)-了、聚(N-异丙基丙烯酰胺)(PS(-b-PNIPAM)-b-PCL)。这种聚合物可以在水溶液中形成以PS/PCL为核、以PNIPAM为壳的胶束,并且这种胶束具有温度敏感性。我们还利用ATRP、ROP和点击化学相结合采用一步法制备了ABC三杂臂星型聚合物,聚苯乙烯(或聚环氧乙烷)-聚(ε-己内酯)-聚(N,N-二甲基胺乙基甲基丙烯酸酯)(PS(-b-PCL)-b-PDMA和PEO(-b-PCL)-b-PDMA)。结合ATRP和点击化学合成了一种新型的具有‘"schizophrenic"聚集性质的ABC三杂臂星型聚环氧乙烷-聚(N,N-二乙基胺乙基甲基丙烯酸酯)-聚(N-异丙基丙烯酰胺)(PEG(-b-PDEA)-b-PNIPAM)。该三杂臂星型聚合物可在酸性和高温的水溶液中自组装形成以PNIPAM为核的胶束,也可在碱性和室温的条件下得到以PDEA为核的反转胶束。还结合ATRP、ROP和点击化学合成了全生物相容性的ABC三杂臂星型聚合物聚环氧乙烷-聚(L-赖氨酸)-聚(ε-己内酯)(PEO(-b-PLL)-b-PCL),这种聚合物在水溶液中自组装形成以PCL为核和以PEO/PLL为壳的胶束。2.合成了包含有三甲氧基硅烷基的嵌段共聚物聚(N-异丙基丙烯酰胺)-b-聚(γ-甲基丙烯酰氧基-丙基三甲氧基硅烷)(PNIPAM-b-PMPS),该聚合物在水溶液中自发形成以PNIPAM为壳层的胶束,在三乙胺催化下硅氧烷水解交联形成氧化硅粒子,从而形成温敏性的二氧化硅/合物杂化纳米粒子。利用嵌段聚合物PDMA-b-PMPS的自组装和自催化凝胶化过程制备了pH和温度敏感的杂化纳米粒子。还合成了端基为多巴胺分子的温度敏感性聚合物PNIPAM,利用配体交换的形式非常简单的制备了温度敏感性的Fe3O4/聚合物杂化纳米粒子。利用ATRP和点击化学合成含有多巴胺衍生物的两亲性三杂臂聚合物聚环氧乙烷-聚(甲基丙烯酸多巴酰胺)-聚苯乙烯(PEO(-b-PDOPA)-b-PS),利用这种聚合物功能化氧化铁纳米粒子,得到了两亲性的氧化铁/合物杂化纳米粒子,发现该粒子在水溶液中能自组装成含有氧化铁纳米粒子的杂化囊泡,这是一种简单的制备杂化纳米囊泡的方式。更多还原

【Abstract】 The supramolecular self-assembly of polymeric building blocks via noncovalent interactions has exhibited important roles in developing novel biomaterials, smart devices, information science, and nanotechnology, which renders this interdisciplinary research subject as one of the key scientific issues in the 21st century. This dissertation mainly focuses on the controlled synthesis, fabrication, and structural tuning of stimuli-responsive supramolecular polymeric assemblies, inorganic/polymer hybrid nanoparticles. A series of amphiphilic and double hydrophilic miktoarm star terpolymers were synthesized. In aqueous solution, chain architectural effects on thier self-assembling properties under varying solution conditions were investigated. Moreover, inorganic/polymer hybrid nanoparticles were investigated. This dissertation can be further categorized into seven main parts as described below:1. Amphiphilic ABC miktoarm star terpolymer consisting of polystyrene, poly(ε-caprolactone), and poly(N-isopropylacrylamide) arms, PS(-b-PNIPAM)-b-PCL, was synthesized via a combination. of atom transfer radical polymerization (ATRP), ring-opening polymerization (ROP), and consecutive click reactions. In aqueous solution, the obtained amphiphilic miktoarm star terpolymer self-assembles into micelles possessing mixed PS/PCL cores and thermo-responsive coronas. We also report on the one-pot synthesis of well-defined ABC miktoarm star terpolymers consisting of poly(2-(dimethylamino)ethyl methacrylate), poly(ε-caprolactone), and polystyrene or poly(ethylene oxide) arms, PS(-b-PCL)-b-PDMA and PEO(-b-PCL)-b-PDMA, taking advantage of the compatibility and mutual tolerability of reaction conditions (catalysts and monomers) employed for ATRP, ROP, and click reactions. We report the first example of synthesis and "schizophrenic" micellization behavior of multi-responsive double hydrophilic ABC miktoarm star terpolymer. A well-defined miktoarm star terpolymer consisting of poly(ethylene glycol), poly(2-(diethylamino)ethyl methacrylate), and poly(N-isopropylacryl-amide) arms, PEG(-b-PDEA)-b-PNIPAM, was synthesized via the combination of ATRP and click reaction. This novel type of miktoarm star terpolymer molecularly dissolves in aqueous solution at acidic pH and room temperature, but supramolecularly self-assembles into PDEA-core micelles at alkaline pH and room temperature, and PNIPAM-core micelles at acidic pH and elevated temperatures. Most importantly, both types of micellar aggregates possess well-solvated hybrid coronas. A well-defined ABC miktoarm star terpolymer consisting of biocompatible poly(ethylene oxide), poly(e-benzyloxycarbonyl-L-lysine), and poly(e-caprolactone) arms, PEO(-b-PZLL)-b-PCL, was synthesized via the combination of consecutive click reactions and ROP. In aqueous solution, the obtained amphiphilic miktoarm star terpolymer self-assembles into micelles possessing PCL cores and mixed PEO/PLL coronas.2. Poly(N-isopropylacrylamide)-b-poly(γ-methacryloxypropyltrimethoxysilane) (PNIPAM-b-PMPS) was prepared by successive reversible addition-fragmentation transfer (RAFT) polymerizations. Thermo-responsive polymer-encapsulated silica hybrid nanoparticles were fabricated via self-assembling of block copolymer in aqueous solution into micelles and subsequent sol-gel process inside the micellar core. And we also report the facile preparation of hybrid nanoparticles starting from a amphiphilic block copolymer, poly(2-(dimethylamino)ethylmethacrylate)-b-poly(γ-methacryloxypropyltrimethoxysilane)(PDMA-b-PMPS), block copoly-mer. Micellization of the obtained amphiphilic diblock polymer in aqueous solution leads to the formation of nanoparticles consisting of PMPS cores and PDMA shells. The PDMA block can spontaneously catalyze the sol-gel reactions of trimethoxysilyl groups within PMPS cores, leading to the formation of hybrid nanoparticles coated with PDMA brushes. PDMA brushes exhibit pH and thermo-responsiveness, the swelling/collapse of them can be finely tuned with solution pH and temperatures. The thermo-responsive dopamine-terminated PNIPAM was synthesized by ATRP, the thermo-responsive Fe3O4/polymer hybrid nanoparticles was obtained through the ligand exchange reaction with dopamine-terminated PNIPAM and Fe3O4 nanoparticles. An amphiphilic ABC miktoarm star terpolymer consisting of poly(ethylene oxide), poly(dopamine methacrylamide) and polystyrene, PEO(-b-PDOPA)-b-PS, was synthesized via a combination of ATRP and click reactions. The amphiphilic Fe3O4 polymer hybrid nanoparticles was obtained through the ligand exchange reaction with PEO(-b-PDOPA)-b-PS and Fe3O4 nanoparticles. In aqueous solution, the amphiphilic hybrid nanoparticles can self-assembles into hybrid vesicles.更多还原