聚电解质巨型分子的水溶液静电自组装及其流变行为研究

The proposal aim of this project is to design and synthesize a class of polyelectrolyte giant molecules (nXPOSS-PEO-nXPOSS) with precise chemical structure and molecular topology based on ionic group-functionalized POSS head group and neutral PEO chain, and obtained a series of novel ordered gel phase through the controlled charge driven-self-assembly of the binary mixture of cationic polyelectrolyte solution and anionic polyelectrolyte solution. The formation and transformation of the ordered gel phase and the corresponding rheological behavior are systematically studied, the relationship between the molecular structure and mixing parameters of the polyelectrolyte giant molecules, the ordered phase and solution rheological behavior are further explored. It is believed that this project will provide a novel POSS-based polyelectrolyte giant molecules synthesis route and obtain ordered gel phase through charge-driven self-assembly, understand relation of the ordered gel phase and rheological behavior in binary mixing solution, which could serve as a powerful platform to further study the self-assembly of polyelectrolyte giant molecules in aqueous solution.

本项目拟设计并合成一类具有精确化学结构和分子拓扑结构的、基于含离子基团官能化POSS头基和中性PEO链的聚电解质巨型分子(nXPOSS-PEO-nXPOSS)。通过含正负离子POSS的聚电解质巨型分子的可控二元共混及其静电自组装，以期获得各种具有不同超分子晶格的有序凝胶相。进一步系统研究其中凝胶相的形成与转变以及对应的流变行为的变化规律，理解这类新型聚电解质巨型分子的分子结构及混合参数与溶液有序相态和溶液流变行为之间的内在关联。本项目将发展一种新颖的POSS基聚电解质巨型分子合成路线，并通过静电自组装获得有序凝胶相，获知其二元混合溶液中有序凝胶相态及其流变行为的关系，为对聚电解质巨型分子在水溶液的组装的理论和应用研究奠定基础。

我们探索了含离子三嵌段聚合物、光响应三嵌段聚合物在溶液中的聚集和流变行为，阐明了不同末端基对聚合物的自组装及流变行为的影响。首先我们通过点击化学、活性聚合等方法合成了一系列两端为聚阴阳离子，中间为中性聚乙二醇链段的三嵌段阴阳离子聚电解质，重点研究了带相反电荷的三嵌段阴阳离子聚电解质二元混合，三嵌段阴离子聚电解质与阳离子表面活性剂二元混合后的静电自组装及流变行为。通过调控溶液浓度，得到了体心立方凝胶相，发现溶液中的相反电荷基团的化学计量比和盐浓度会显著影响凝胶相流变行为，且凝胶相的松弛行为符合时间-浓度/盐浓度叠加，表明溶液松弛行为主要由阳离子-阴离子对的静电相互作用决定的。在已有研究成果的基础上构建了光响应三嵌段聚合物的新思路，主要是利用具有光响应夺氢偶合的二苯甲酮、自由基聚合的双键、光二聚的香豆素作为三嵌段聚合物的疏水末端基，探讨三嵌段聚合物的光响应分子结构转变对溶液黏弹性的影响，提出了类橡胶交联的凝胶化过程解释有关现象，并进一步探索了其在光固化树脂中的应用。进一步搭建UV-DoS测试装置，阐明了三嵌段聚合物水溶液的应变硬化机理。上述结果对理解含离子三嵌段聚合物、光响应三嵌段聚合物在溶液中的动力学行为具有一定的意义。