高分子逐级自组装过程中纳米聚合物的“合成”、组装及相应机制研究

Step-wise self-assembly is promising strategy to construct assemblies with higher-level hierarchy and complexity, which has been the frontier development of self-assembly. In the step-wise self-assembly, the primary assemblies first form one-dimensional structures, and then further self-assemble into hierarchical structures. This is akin to the synthesis of polymers and their self-assembly process, but the length scales are different. However, the fundmental problems such as the driving force and kinetics of “polymerization” of primary assemblies, which determine the step-wise self-assembly, are still unclear. In this proposal, we aim to investigate these fundamental problems by theory and simulation to gain insight into the self-similarity and dynamics in the systems. The investigation is based on the anisotropic primary assemblies formed by rod-coil copolymers and multiblock copolymers. Guided by theory and simulation, we aim to prepare the primary assemblies with various structures in experiments and then investigate the step-wise self-assembly of the primary assemblies. Through the studies, we anticipate extending the concepts of polymer synthesis and polymer self-assembly to a higher level and providing guides for the preparation of one-dimensional nano-materials and materials with structural hierarchy.

高分子自组装已发展到精确构建更大尺度、更复杂组装体的重要阶段。利用初级组装体的“聚合”（一维自组装）形成纳米聚合物、再通过纳米聚合物的组装形成多级结构的逐级自组装是最有前景的一种方法，其关键是控制初级组装体的“聚合”制得纳米聚合物。然而，对初级组装体的“聚合”驱动力和“聚合”动力学等基本问题还不清楚。本项目拟以刚柔共聚物和多嵌段共聚物形成的各向异性初级组装体为主要研究对象，利用理论或模拟，研究它们的“聚合”及相应纳米聚合物的组装，从而阐明逐级自组装中的自相似性特征。以理论或模拟为指导，在实验上合成不同类型的初级组装体，并对其进行相应的逐级自组装研究。通过研究，以期将高分子合成和自组装的概念拓展到更大的尺度，为新型一维纳米材料及多级结构材料的精确制备提供思路和方法。

由高分子制备微纳结构，尺度跨度大，在形成过程中往往存在着大量亚稳态，使得微纳结构的尺寸分散性较大。为解决这一科学问题，本项目将逐步聚合、链式聚合和环化反应等概念推广到微纳尺度，发展了利用低层次结构的“聚合”或“反应”构建高层次结构的非平衡态动力学调控方法，包括末端缺陷诱导的再组装、排空作用下的再组装、液晶驱动自组装、棒状胶束的超分子环化、聚合诱导胶束再组装和表面诱导胶束再组装等，实现了多级微纳结构的精确制备，并基于理论模拟阐明了超分子聚合或反应的本质。研究工作为制备均一的多级组装体提供了思路，同时奠定了相关理论基础。研究成果发表在Nano Letters、Nanoscale、Macromolecules、Polymer、高分子学报等本领域重要期刊上，共发表标注基金号的SCI论文23篇，并作各类学术报告6次。项目执行期间，辅助培养博士毕业生5名，培养硕士生2名。