光敏性POSS杂化共聚物的多重逐级响应自组装研究

How to combine composition, topology and functionality is a big challenge for the design of a polymer architecture. Polyhedral oligomeric silsesquioxane (POSS), a new organic/inorganic hybrid material, has a cubic-shape structure with the possibility of precise chemical modification at each of the eight corners. Photo-responsive spiropyran compound can reversibly transform between the closed spiropyran form and the open merocyanine form under the irradiation of UV and visible light. The change of the molecule polarity induced by the conversion of the structure endows the spiropyran-containing polymers a broad potential use in photo controllable self-assembly. In this study, we will design and synthesize POSS-modified spiropyran-containing polymers with different topologies by combining the atom transfer radical polymerization (ATRP) and click chemistry and investigate the controlled self-assembly behaviors in solution system. POSS molecule can induce the self-assembly behavior because of its low surface energy; besides, it introduces the excellent properties of the inorganic components into the polymeric micelles, and improves the morphological stability of the micelles as well as the light and thermal stability of the photo-responsive polymers. Moreover, we hope to prepare a multi-responsive polymer by introducing a temperature-/pH-responsive component in order to realize a step-by-step response. This study has a theory and practical significance in controlled release, sensing and separation.

在聚合物的分子结构设计中，有效地将聚合物组成、形态和功能性结合在一起，是未来聚合物材料发展的一个新的趋势和挑战。本课题采用原子转移自由基聚合（ATRP）和点击化学设计合成不同拓扑结构的POSS修饰的螺吡喃光敏性聚合物，并将其应用于溶液组装领域。POSS因其低表面能在水溶液中能够诱导组装的发生，同时也将无机组分的热力学特性引入光敏性聚合物的自组装体中，可以改善聚合物胶束应用于可控释放领域时形态稳定性差、光敏性聚合物耐光热稳定性差等问题。通过研究该类POSS基螺吡喃光敏杂化聚合物在不同溶液体系中组装过程，以达到可逆控制其形态的目的。同时引入pH敏感和温度敏感的聚甲基丙烯酸二甲氨乙酯嵌段，以期达到多重刺激响应，有望实现聚合物组装形态的逐级响应，这对该类聚合物应用于可控释放、传感、分离等领域有着理论和实际的指导意义。

本项目在聚合物的分子结构设计中，有效地将聚合物组成、形态和功能性结合在一起，是未来聚合物材料发展的一个新的趋势和挑战。本课题采用原子转移自由基聚合（ATRP）和点击化学设计合成不同拓扑结构的POSS修饰的螺吡喃光敏性聚合物，并将其应用于溶液组装领域。POSS因其低表面能在水溶液中能够诱导组装的发生，同时也将无机组分的热力学特性引入光敏性聚合物的自组装体中，可以改善聚合物胶束应用于可控释放领域时形态稳定性差、光敏性聚合物耐光热稳定性差等问题。通过研究该类POSS基螺吡喃光敏杂化聚合物在不同溶液体系中组装过程，以达到可逆控制其形态的目的。同时引入pH敏感和温度敏感的聚甲基丙烯酸二甲氨乙酯嵌段，以期达到多重刺激响应，有望实现聚合物组装形态的逐级响应，这对该类聚合物应用于可控释放、传感、分离等领域有着理论和实际的指导意义