温敏性球形聚合物刷的聚集和解聚行为

The aggregated states of thermoresponsive spherical polymer brushes in solution play a crucial role in their biomedical applications. Current progress mainly focuses on the phase transition behavior of a single spherical polymer brush, whereas the aggregation-disaggregation behaviors of thermoresponsive spherical polymer brushes in solution are still lack of systematic research. Here, we will design and prepare model systems from neutral thermoresponsive polymers grafted silica hybrid nanoparticles. Through manipulating inter/intra interactions(including hydrogen bondings and hydrophobic interactions), the dimensional, morphological, thermal and structural changes of thermoresponsive spherical polymer brushes during the aggregation-disaggregation process in aqueous solutions will be investigated intensively, using several techniques including laser light scattering(LLS), transmission electron microscope(TEM), microcalorimetry(US-DSC) and small angle X-ray scattering(SAXS). The relationship between different impact factors (such as the chemical composition, structural parameters and environmental conditions) and the aggregated states of the thermoresponsive spherical polymer brushes can be established; physical models and phase transition mechanism during the kinetic process will be proposed. It is anticipated that this research will not only provide effective regulation of the aggregation behaviors of the thermoresponsive spherical polymer brushes, but also give valuable insight to some fundamental problems such as protein aggregation in life science.

温敏性球形聚合物刷在溶液中的聚集状态对其在生物医药领域中应用具有重要影响，但目前的研究集中在单个球形聚合物刷的相转变行为，而对于温敏性球形聚合物刷在溶液中的聚集和解聚行为尚缺乏系统研究。本项目拟设计和制备系列以球形二氧化硅纳米粒子为核、表面接枝中性温敏聚合物刷（温敏性球形刷）的模型体系，通过调控刷内部、刷之间多种相互作用（包括氢键、疏水相互作用等），利用激光光散射、透射电镜、微量量热仪、小角X-射线散射等手段，深入研究温敏性球形聚合物刷在聚集和解聚的相转变过程中的尺寸变化、形貌变化、热量变化和结构变化，建立体系化学组成、结构参数、环境条件与温敏性球形聚合物聚集状态之间的构效关系，给出聚集和解聚动力学过程的物理图像，提出转变机理，以期实现对温敏性球形聚合物刷聚集状态的有效调控，同时也能为蛋白质聚集等生命科学中的一些基本问题提供有价值的参考。