基于组装单体的RAFT聚合构建功能聚合物微纳米管

This project describes an approach to fabricate polymer micro- and nano-tubes via “polymerization and dissolution simultaneously of the assembled monomers”, which involves two steps: (1) assembled monomers with different sizes and morphologies will be assembled from acrylamide type monomers, and (2) the RAFT polymerization of the assembled monomers will be carried out to prepare polymer tubes directly. The transformation conditions will be investigated for various kinds of assembled monomers, especially for nano-sized assembles. Polymer tubes with different surface microstructures will be fabricated via controlling the RAFT polymerization conditions and solution product morphologies. The functionalization of polymer tubes will be realized through the methods of copolymerization or post polymerization involving functional monomers. The combination of functionalization and regulation technique of surface microstructure will lead to functional polymer tubes with different surface microstructures. The adjusting role of RAFT polymerization and the technique for controlling morphologies and structures of the products will be obtained based on the investigation of formation mechanism of polymer tubes. The relationship between the structure parameters (including morphologies, sizes and microstructures) and functions of polymer tubes will be established via determining the adsorption and releasing performances for guest molecules. The fabrication method of polymer tubes developed in this project have the characters of simplicity, high efficiency and easy controlling in the morphologies, which will enrich the preparation techniques of polymer tubes and provide novel approach for constructing other hollow polymer micro- and nano-structures.

本项目提出通过“组装单体边聚合边溶解”途径制备聚合物微纳米管，该制备过程包括两步：（1）丙烯酰胺类单体组装成不同尺度及形貌的组装单体；（2）通过组装单体的RAFT聚合直接制备聚合物管。探索各种类型组装单体特别是纳米组装单体的转化条件。通过控制RAFT聚合条件及溶液产物形貌，构建具有不同表面微结构的聚合物管。通过功能单体的共聚合、分步聚合等方法，实现聚合物管的功能化，并通过结合表面微结构调控技术，制备具有不同表面微结构的功能聚合物管。通过研究聚合物管的形成机理，明确RAFT聚合的调控作用，并建立控制产物形态结构的技术。通过测定不同功能化聚合物管对客体分子的吸附及释放特性，揭示结构参数（包括形态、尺度、表面微结构等）与功能的关系。本项目发展的构建聚合物管的方法，具有简单、高效、形貌易于控制的特点，丰富了聚合物管的制备技术，并为其他中空聚合物微纳米结构的制备提供一条全新途径。

本项目系统研究了氢键超分子体系的构建、模板合成聚合物以及材料的特性及功能。以氢键型可聚合有机凝胶为模板，采用RAFT聚合制备了多种聚合物微纳米管线，之后，通过管上活性基团的化学反应，制备了多种功能化管状聚合物材料，包括Cr(VI)的吸附剂、亚甲基蓝的吸附剂、检测铜（Ⅱ）的荧光传感器。发现溶剂极性影响到聚合速率和聚合物纤维的微观结构。随着溶剂极性增加，可以获得表面更粗糙、尺寸更大的纤维。样品的比表面积影响了对酸性靛蓝的吸附能力。以环己烷为溶剂，进行二脲型纳米凝胶的普通自由基聚合，也可获得表面光滑的聚合物纳米线。此外，以金属凝胶为模板，通过单体聚合，制备了功能聚合物纳米管线，聚吡咯纳米线网络具有良好的力学性能、较大的比表面积及优异的电化学特性。通过改变氢键取代基的推拉电子作用，从简单的氢键类型（包括酰胺键、脲键、氨基甲酸酯键）出发，构建了多种氢键超分子聚合物和聚氨酯-聚脲-聚丙烯酸酯杂化材料，揭示了氢键作用对材料物性和功能的影响。基于可逆共价键，设计制备了多种功能性分散剂，并实现药物分子的高效包埋及可控释放。最后，采用一步RAFT聚合途径，实现在各种表面上高效接枝聚合物纳米线网络。