基于杯芳烃液晶的新型液晶交联聚合膜的制备与光致形变性能

Light-induced deformation material is one of the important research field of light-responsive smart materials. Up to now, these materials were synthesized by crosslinking long aliphatic chain liquid crystal monomer with azo group polymerized monomer liquid crystal. As result, these materials have the defect of lower efficiency of light isomerization due to the small liquid crystal temperature ranges, the tight crosslinking structures and the large steric hindrance for the rotation of N=N bond isomerization. This application firstly proposed to synthesize novel liquid crystal crosslinking polymeric film by using supramolecular liquid crystal with three-dimensional cavity structure (triphenylene - azo - calixarene derivatives) as monomer and then crosslinking with the appropriate dual-or single olefin. These novel polymeric films will maintain the advantages of low phase transition temperature and wide mesophase temperature range of triphenylene liquid crystal. Moreover, the two-dimensional structures of triphenylene liquid crystal has better deformation rate than that of one-dimensional aliphatic chain and the cavity of the three-dimensional structure of calixarene possess better rotation freedom for N = N bond isomerization, resulting in the short responsive time and high efficiency of the photoisomerization. This application will study systematically the preparations, structures and light-induced deformation performances of these novel films, focused on solving basic scientific problems of convenient preparation, structural and conformational control, the relationship between structure and light-induced deformation properties, and key influencing factors of these novel polymeric films. In a word, this study will establish the new theoretical foundation for the design and synthesis of novel light-induced deformation materials with excellent properties.

光致形变材料是光响应智能材料领域重要研究领域之一。目前这类材料主要由带偶氮基的长脂肪链烯烃液晶单体交联聚合而成，存在单体液晶相温度范围较小，且交联形成的较紧密结构对异构化时N=N键的旋转产生较大位阻，导致光异构化的效率较低等缺陷。本申请首次提出以带三维空腔结构的超分子液晶（苯并菲-偶氮-杯芳烃衍生物）为聚合单体，与适当结构的双或单脂肪链烯烃液晶聚合制备新型液晶交联聚合膜。这种新型聚合膜将不仅保持聚合单体液晶转变温度低和液晶相温度范围宽的优点，而且在光异构化时二维的苯并菲液晶单元比一维脂肪链具有更好的形变率，同时杯芳烃的三维空腔结构给予N=N键异构化旋转较大自由度，缩短响应时间，提高光异构化效率。本申请将系统研究这种膜的制备、结构与光致形变性能，重点解决它们在可控制备、结构调控与光致形变性能之间的构效关系及关键性影响因素等基础科学问题，为具有优异光响应性能的新型智能材料研究奠定新的理论基础。

本项目主要开展了6个方面的研究工作，并取得显著进展，具体包括：(1)设计并合成了一系列新型杯芳烃-苯并菲液晶、杯芳烃-胆固醇液晶、杯芳烃-没食子酸液晶，研究了结构与性能之间的关系，发现构象的灵活性对液晶性能有较大影响，探索了客体诱导下的液晶性能转变行为，结果表明客体识别可以诱导液晶-晶体之间的转变；（2）设计并合成了一系列苝-苯并菲液晶，研究了不同结构与取代模式对发光性能和液晶性能的影响，首次报道了湾位取代的苝液晶的高度有序六方相液晶及大斯托克位移发光能力及良好的固体发光性能；（3）首次报道了一系列苯并菲-BODIPY发光液晶的设计、合成与性能研究，探讨了以苯并菲为核的新型BODIPY发光液晶的高效发光能力，为BODIPY发光液晶开辟了新的研究思路；（4）报道了系列具有聚集诱导发光性能的新型苯并菲发光液晶，总结了AIE单元的结构与数目对苯并菲液晶性能与发光性能的影响；（5）含氢键的一系列新型液晶分子的设计、合成与性能研究；（6）研究了系列新型杯芳烃聚合物的制备与对染料分子的高效吸附能力，筛选了具有高选择性吸附能力的杯芳烃聚合物材料。截止目前，以上工作共发表SCI论文34篇，其中二区以上8篇，三区以上18篇，被引用101次。