Fluorescence Study on Microstructure and Phase Transition Dynamic of Polymer Gels and Polymer Liquid Crystals

利用荧光技术研究聚合物凝胶和聚合物液晶的微观结构和动力学特性。得到了以下结果：1)采用丹酚探针研究了聚丙烯酰胺和聚n -异丙基丙烯酰胺凝胶的荧光光谱和荧光去极化。此外，研究了氘取代效应，阐明了氢键在聚合物凝胶膨胀和破裂中的作用。2)以芳香族聚酰亚胺为原料，以羟基和二异氰酸酯为交联剂，首次制备了一种新型耐热性聚酰亚胺凝胶。3)对不同类型LC聚合物和低分子量液晶进行了主链芳香族液晶聚合物介生基间微观结构及其动力学的荧光研究。利用手性亚砜的光转化实现了胆甾液晶的光控制。4)荧光技术还应用于其他具有纳米级有序结构的聚合物体系和倒转胶束体系。

This research was carried out in order to elucidate microstructure and dynamics of polymer gels and polymer liquid crystals by using fluorescence method. The following results were obtained.1)Fluorescence spectra and fluorescence depolarization of polyacrylamide and poly-N-isopropylacrylamide gels were studied by incorporating a dansyl probe. Moreover, deuterium substitution effect was studied for elucidating the role of hydrogen bonding in expansion of collapse of the polymer gels.2)A new thermostable polyimide gel was first prepared from an aromatic polyimide with hydroxyl groups and diisocyanate crosslinker.3)Fluorescence study on microstructure between mesogenic groups in main-chain aromatic liquid crystalline polymers and their dynamics was carried out for various-type LC polymers and low-molecular-weight liquid crystals. Photo-control of cholesteric liquid crystals by using photoinversion of a chiral sulfoxide was also realized.4)Fluorescence technique was also applied to other polymer systems with nano-scale ordered structure and inverted micelle systems.