糖化学推动的嵌段共聚物的自组装研究

诱导嵌段共聚物溶液自组装的途径有多种，包括传统的选择性溶剂和利用嵌段的环境敏感性等方法。与之相比，通过化学反应诱导嵌段共聚物自组装的方法发展得不够充分。本课题首次提出将糖化学，特别是寡糖合成的保护基化学引入自组装，即利用糖的脱保护反应诱导糖嵌段共聚物在有机溶剂中组装。随后通过选择性溶剂切换法，诱导组装体进行形貌调整或二次组装。由于糖分子本身的结构复杂性，目前制备多种立体化学明确的糖聚合物必须通过保护-脱保护过程。本课题将脱保护与自组装结合，可充分利用保护基的多样性和相应反应条件的可控性，从热力学或动力学等方面控制组装体的形成过程和组装体形貌。这样，本课题不仅能够基于糖化学发展化学反应诱导嵌段共聚物自组装的全新途径，更可对糖单元的特有结构因素对嵌段共聚物自组装的影响获得深入的理解。

Quite a few methods have been employed to induce self-assembly of block copolymers in solution. The classical selective solvent method and use of responsive blocks have attracted a lot of attention. Compared to the two methods, that block copolymer self-assembly induced by chemical reactions is less developed. In this project, for the first time we plan to introduce carbohydrate chemistry, especially the protective group chemistry in oligosaccharide synthesis to macromolecular self-assembly, i.e. using deprotection reactions to induce the self-assembly of sugar-containing block copolymers in organic solvent. Then by switching the solvent, the self-assembled nano-objects can adjust their morphology or even re-assemble. Because of the complexcity of chemical structure of sugars, protection and deprotection reaction in preparation of glycopolymer is inevitable, if a distinctive anomeric linkage is desired. Thus by combining the deprotection and self-assembly process, we will be able to realize effective control on the self-assemble process kinetically and thermodynamically via using different protective groups and deprotection conditions. In short, this project is expected not only to open a new avenue for chemical-reaction-induced self-assembly of block copolymers,but also to gain deeper understanding of the effects of the various structural factors of sugar units on the self-assemble behavior of the block copolymer in solution.