含聚集诱导发光基团侧链聚苯乙炔的合成、结构及偏振发光行为的研究

The low energy conversion efficiency, complicated device design, and low brightness of traditional optical electronic devices due to the use of polarizer can be solved by by linearly or circularly polarized luminescence (LPL or CPL) provided by luminescent liquid crystals. Traditional luminescent liquid crystalline materials faced the deficiency of low luminescent quantum yield, low polarized ratio or low emission dissymmetry factor because of the notorious aggregation caused quenching. Thus, the research of polarized emission based on luminescent liquid crystal is very important.. By introducing aggregation induced emission (AIE) groups and chiral center to the side chains of polyphenylacetylenes (PPA) would form sheet-like or column-like structure with high shape persistence. The resultant side-chain liquid crystalline PPA (SCLCPPA) can be LPL or CPL with high efficiency and high polarized ratio/high emission dissymmetry factor. In this proposal, diphenylacetylene, cyano-diphenylethene and tetraphenylethene will be introduced to the side chains of PPA to form SCLCPPA with sheet-like or column (helical structure) structure. By using thermal analysis, polarized light microscopy, one and two dimensional X-Ray diffraction, steady and time resolved fluorescence spectroscopy and other methods to investigate the polymeric molecular shape, liquid crystalline behavior and phase structure, photoluminescence of the solution and thin film, based on which, we will investigate the polarized luminescence.. This project will illuminate the relationship of phase structure and polarized luminescent behavior of SCLCPPA, and pave the way of design and preparation, structure and properties of polarized luminescent materials by providing theoretical and experimental results.

传统光电器件由于使用偏振片而引起的能量转换效率低、器件设计复杂及亮度低等问题有望通过发光液晶能发射线/圆偏振光得到解决。然而，传统发光液晶材料存在聚集导致猝灭引起的效率低且偏振性能较差等缺点。因此，对基于发光液晶的偏振发光研究具有重要意义。. 将聚集诱导发光（AIE）基团及手性中心引入聚苯乙炔（PPA）侧链将能够形成具有片状或柱状结构的有序堆积以发射高偏振比/不对称因子的线/圆偏振光。本项目拟将具有AIE效应的二苯乙炔、氰基二苯乙烯及四苯基乙烯引入PPA侧链以形成片状或柱状结构，采用热分析、偏光显微镜、一维和二维X-射线衍射、稳态和瞬态荧光光谱等多种研究手段考察其单分子形状、本体相结构、溶液及薄膜发光行为，并在此基础上进一步考察其偏振发光行为。. 本项目将揭示发光性侧链PPA相结构与偏振发光行为之间的关系，为新型发光材料的一般性设计、结构与性能的研究提供理论和实验依据。

针对传统液晶不能主动发光，需要使用背光源的被动发光问题，本项目拟通过发光液晶的主动发光给予解决。因此，本项目的研究在基础研究和应用研究方面均有较为重要的意义。本项目将聚集诱导发光（AIE）基团（二苯乙炔、四苯基乙烯及氰基二苯乙烯等）引入聚苯乙炔（PPA）等刚性主链的侧链形成刚性主链的发光液晶高分子或直接连接到聚乙烯侧链形成甲壳型液晶高分子，通过调节烷基尾链长短、间隔基长度及AIE基团以达到调控发光液晶高分子本体相结构与发光行为之间的关系。. 本项目的具体研究内容包括侧链含氰基二苯乙烯的刚性主链高分子的合成、结构和性能研究；侧链含二苯乙炔的聚苯乙炔衍生物的合成及性能研究；侧链含四苯基乙烯的聚乙炔衍生物的合成及性能研究；基于侧链含四苯基乙烯的甲壳型液晶衍生物的合成及性能研究；基于侧链含间苯二甲酸酯的甲壳型液晶聚合物的合成及性能研究；基于四苯基乙烯的分子间/分子内能量转移发光液晶分子的合成及性能研究。. 本项目揭示了发光液晶聚合物发光行为与相结构之间的关系，为新型发光材料的一般性设计、结构与性能的研究提供了理论和实验依据。