两亲性聚合物刷的合成和溶液自组装  

Synthesis and Solution Self-assembly of Amphiphilic Molecular Bottlebrushes

作　　者：隆美林 张科[1] 陈永明[1,2] 朱雯[1] 

机构地区：[1]中国科学院化学研究所,北京100190 [2]中山大学材料科学与工程学院,广州510275

出　　处：《高分子学报》2016年第9期1238-1246,共9页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号21374122,51203171)资助项目

摘　　要：结合可控自由基聚合和铜催化的叠氮-炔环加成(Cu AAC)反应,合成了一系列Ab BA型两亲性的聚合物刷.其中A段为亲水性的聚(N,N'-二甲基丙烯酰胺)(PAm);B段为高密度接枝的聚合物刷,其侧链为疏水性的聚苯乙烯(PS).通过核磁氢谱(1H-NMR),凝胶渗透色谱(GPC)表征了聚合物刷的组成及结构,其侧链接枝密度约为100%.研究了亲水链段含量不同的聚合物刷在多种条件下的溶液自组装行为,通过透射电子显微镜(TEM)表征了组装体的形貌.在相同的组装条件下,两亲性聚合物刷中亲水链段含量较高时(>5%),组装体形貌为球形,而随着亲水链段含量降低,形貌向片层状胶束和囊泡转变.对聚合物刷PAm195-b-(PA-g-PS67)153-b-PAm195的自组装研究表明,提高初始浓度促使组装体形貌向片层和囊泡转变;采用与PS的溶度参数相近的良溶剂,可提高胶束核的活动性,组装体更容易形成囊泡(热力学稳定态);而采用与PS的溶度参数相差大的选择性溶剂时,组装体倾向于聚集形成大尺寸的囊泡.Well-defined AbBA triblock bottlebrushes with the poly（N,N＇-dimethyl acrylamide） （PAm） as A block and polyaerylate densely grafted with polystyrene （PS） as B block were prepared by the combination of controlled radical polymerization and copper-catalyzed azide-alkyne cyeloaddition （CuAAC） reaction. The composition and structure of the bottlebrushes were confirmed by hydrogen nuclear magnetic resonance （1H- NMR） and gel permeation chromatograph （GPC）,which showed a high side-chain grafting density of about 100%. The self-assembly behavior of the bottlebrushes with different PAre contents was investigated under various conditions. The morphologies of assemblies were observed using transmission electron microscope （TEM）. Under the identical condition, the amphiphilic bottlebrushes with higher PAm content （ 〉 5% ） selfassembled into sphere micelles, while the bottlebrushes with lower PAre content trended to form lamellar mieelles and vesicles. The effects of initial concentration and solvents were investigated using PAm195-b-（PA-g- PS67 ） 153-PAm195 under different conditions. The increase of the initial concentration changed the micelles from spheres to lamellae/vesieles. A common solvent with the solubility parameter closer to PS increased the mobility of the PS chains in the core, and led to assemblies of vesicles （ thermodynamics steady state） ; while a selective solvent with the solubility parameter differed greatly from PS led to aggregation to form larger vesicles.

关 键 词：两亲性 柱状聚合物刷 自组装 囊泡 形貌变化 

分 类 号：O631[理学—高分子化学]