新型主链型荧光共轭聚电解质的合成与传感性能研究

Up to now, water-soluble conjugated polyelectrolytes with the ionic pendants have achieved great success in acting as fluorescent sensor. While as a promising candidate for fluorescent sensing material, the present research on conjugated polyelectrolytes with ionic main chain has been rather limited and far behind that of conjugated polyelectrolytes with the ionic pendants. The important factor that has great impacted on the development of these materials used as fluorescent sensor is low water-solubility and fluorescent quantum yield caused by poorly emissive properties of ionic units and low charge density of polymers. To overcome this intrinsic deficit, a new strategy for design and synthesis of conjugated polyelectrolytes with ionic main chain will be proposed in this application. We will adopt ionic units with highly emissive properties and hydrophilic side chains to construct novel conjugated polyelectrolytes with ionic main chain, providing them for highly fluorescence quantum yield and water-solubility. On this basis, synthesis method and fluorescent sensing properties of new materials will be investigated in depth and systematically. We strive to gain the innovative scientific achievements in aspects of molecular designs, material systems, detection methods and sensing applications. Based on our efforts, this new strategy will pave a way for development of ionic main chain conjugated polyelectrolytes with novel structures.

针对目前国内外对共轭聚电解质荧光传感材料的研究以侧链型共轭聚电解质体系为主，而主链型共轭聚电解质虽具有作为荧光传感器的潜力，但发展缓慢的现况，本申请围绕制约主链型共轭聚电解质传感应用和发展的重要因素- - 发光性能和水溶性，通过突破离子化单元发光性能弱和聚合物电荷密度低的关键问题，采用高发光性能的和含亲水链的离子化单元，制备和发展具有高水溶性和高荧光量子效率的主链型共轭聚电解质，并深入系统地研究它们的合成方法和荧光传感性能，力争在分子设计、材料体系、传感检测方法与应用等方面为主链型共轭聚电解质的研究开辟出新途径和取得创新性基础成果。

本项目围绕设计和开发新型共轭高分子荧光传感材料，利用细乳液聚合制备超支化共轭高分子纳米粒子的合成方法，通过对纳米粒子核心结构单元和末端基团的调控，制备出一系列溶液可分散的功能性荧光超支化共轭聚合物纳米粒子，发展新型共轭高分子荧光传感器及传感薄膜。（1）利用细乳液Suzuki聚合，开发出不含任何乳化剂，并具有溶液加工特性的多孔超支化共轭高分子纳米粒子。基于多孔结构有利于分析物分子扩散进入材料内部，增强检测效果的优势，制备出检测爆炸物的多孔纳米粒子旋涂薄膜以及试纸，有效提高了硝基芳烃类爆炸物蒸汽及固体颗粒的检测灵敏度。（2）利用细乳液Suzuki聚合的封端反应以及纳米粒子后功能化反应，制备出末端具有功能基团的超支化共轭高分子纳米粒子，实现了端基对纳米粒子的电子和光学性质、分散性能和传感性能的有效调控：①制备出首例基于从纳米粒子核心到端基的荧光共振能量转移（FRET）机制检测CN-阴离子的超支化共轭高分子纳米粒子荧光增强和比例荧光传感器；②开发了首例利用从纳米粒子核心到端基的分子内电荷转移（ICT）机制调节电子和光学性质的共轭高分子纳米粒子，并用于高灵敏度检测有机溶剂四氢呋喃中的微量水；③制备出具有亲水性磺酸盐末端的水分散超支化共轭高分子纳米粒子，并利用其水内核与TNT分子之间的疏水富集作用，高灵敏度和高选择性的检测水中的TNT分子。