具有力致变色和AEE特性的苯胺齐聚物衍生物及其聚合物的结构设计与性能调控

Ordinary organic materials present weak fluorescence efficiency in the solid state because of the aggregation-caused quenching (ACQ) effect. On the contrary, the materials possessing aggregation-induced emission (AIE) or aggregation-enhanced emission (AEE) features can emit fluorescence more efficiently in the aggregated state than in the dissolved form, which have attracted considerable research interests for their valuable academic and application potentials in various fields. Based on the preliminary research results, a series of oligo-aniline derivatives substituted with diphenyl-enamine groups will be synthesized with tunable oligo-aniline length, diphenyl-enamine group contents and sequences derived from structure-desired aniline oligomers. Then the oligo-aniline derivatives with functional end groups will be introduced into the polyurethane soft or hard segments to give novel polyurethane materials with controllable soft and hard segment structures, contents, molecular weights and functions. The influence of soft and hard segments structure types, contents, molecular weight and the position and contents of oligo-aniline derivatives on the polymer properties including AEE features will be investigated in detail, and novel AEE compounds and polymers will be developed based on the rational structure design and preparation. Furthermore, the role of diphenyl-enamine groups playing in the relationship between oligo-aniline derivatives and polymers and their performances will be studied, their AEE mechanisms will be set up based on their molecular and aggregation structure investigations and adjustments. Finally, the mechanofluorochromism features and mechanisms of oligo-aniline derivatives and their polymers will be investigated, and the application as high-sensitive stress sensors will be developed based on our understanding towards the structure-property relationship of these materials. This project will focus on the following issues: the relationship between the contents and sequences of diphenyl-enamine groups in oligo-aniline derivatives and their AEE properties, the influence of the molecular and aggregation structures of polyurethanes modified by oligo-aniline derivatives on the AEE properties, and the mechanism of stress-induced fluorescence enhancement.

具有聚集诱导发光或聚集增强发光(AEE)性质的材料从根本上克服了传统荧光材料在聚集时荧光猝灭的难题，受到国内外学者的广泛关注。本项目通过控制苯胺齐聚物长度、二苯烯胺取代基含量和序列结构等，获得一系列二苯烯胺取代的苯胺齐聚物衍生物。进一步将端基官能团化的二苯烯胺取代的苯胺齐聚物衍生物引入聚氨酯软段或硬段中，并通过对聚氨酯软硬段结构、含量、分子量和AEE基团在聚氨酯链上的位置和含量等的合理设计和制备，发展新型AEE分子及其聚合物体系。通过对其分子链结构和聚集态结构的调控，揭示二苯烯胺取代基进入苯胺齐聚物骨架对材料性能影响的本质，探讨这些小分子及其聚合物的AEE发光机理。最后研究苯胺齐聚物衍生物及其聚合物的力敏感变化规律和发光机制，发展高灵敏力传感器。本项目拟重点解决苯胺齐聚物衍生物中二苯烯胺含量和序列结构、改性聚氨酯分子链和聚集态结构对材料AEE性能的影响以及这些材料的力致荧光增强的机理问题。

如何从根本上克服传统荧光材料在聚集时会发生荧光猝灭（ACQ）的难题受到国内外学者的广泛关注。本项目首先合成了由二苯烯胺或苯酰基取代、端基修饰的不同链长的苯胺齐聚物衍生物，发现苯胺链长、端基及插入的取代基种类和数目不同都可以有效调节苯胺齐聚物衍生物的发光波长和荧光量子产率。通过对苯胺齐聚物的链长度、取代基和端基结构的精细设计，可以实现苯胺齐聚物衍生物从ACQ到聚集诱导发光(AIE)的转变，创新性提出通过链插入模式(Chain-insertion)获得ACQ-AIE转换的AIE体系设计策略，取代基种类和数目的有效调控是使线型苯胺齐聚物结构实现特定AIE性能的有效方法。. 研究了这些AIE特性的苯胺齐聚物衍生物在力、化学和生物等多重刺激响应方面的检测机理，发现在力、溶剂、有毒痕量苯、金属离子（如Ag+、Fe3+等）、蛋白质检测和细菌选择性成像方面表现出优异的特异性识别能力，有很好的应用前景。.进一步设计制备出带端氨基和柔性醚链的1,1,4,4-四芳基丁二烯（TABD）衍生物及二苯烯胺取代的苯胺四聚体衍生物，以及带端羟基的TABD-OH小分子。将这些具有AIE特性的TABD基团或苯胺四聚体衍生物引入到聚氨酯(PU)中，制备出一系列具有聚集增强发光(AEE)特性的新型PU，发现AIE基团含量及其在PU软硬段的位置、PU软硬段比例等都会明显影响PU的AEE性能，通过对PU分子链结构和聚集态结构的调控可以揭示AIE基团的结构和性能对聚合物性能影响的本质，建立了AEE聚氨酯凝聚态结构与其荧光发光强度的关系。. 最后通过热处理、溶剂熏蒸和拉伸等方法实现了对聚氨酯凝聚态结构和荧光性能的调控，揭示了AEE聚氨酯对氢卤酸气体/氨气体系、金属离子、不同爆炸物、应力的检测能力及检测机理，获得了多种高灵敏度、低成本的检测体系，在力、化学、温度等多重刺激响应方面具有潜在的应用价值。. 本项目在首次实现苯胺齐聚物衍生物的ACQ-AIE转变及荧光性能调控、建立AEE聚氨酯分子链和凝聚态结构与其AEE性能关系、揭示其多重刺激响应机理及应用方面具有明显特色和创新，获得了多种新型AIE分子及其聚合物体系。