聚合物/液晶有序复合材料的结构调控与性能

激光全息技术是高分子材料有序复合的重要方法，本项目以聚合物/液晶体系为对象，通过分子设计原理、乳液界面原位共聚法和表面修饰技术，合成纳米-亚微米液晶微胶囊类流体、乙烯基纳米二氧化硅类流体和烷基化纳米二氧化锆。利用超支化单体、类流体和液晶在可见光聚合中的降粘作用，调控激光全息光聚合过程中单体/液晶/纳米无机粒子复合体系的相分离，使液晶微胶囊、高折射率的烷基化纳米二氧化锆和液晶复合体定位于相干条纹暗区，形成复合液晶相以增加聚合物/液晶有序复合材料的折射率对比度；将与聚合物折光率相近的乙烯基多面体低聚倍半硅氧烷或乙烯基纳米二氧化硅类流体定位于相干条纹亮区，形成复合聚合物相以克服体积收缩。研究相分离、体积收缩、折射率对比度等协同效应对有序复合材料结构与光栅性能的影响，探索三维全彩色图像存储和电光响应光栅应用，丰富、发展高分子有序复合理论，为制备高性能高分子有序复合材料提供理论基础和新方法。

Holography is one of the most significant techniques to fabricate ordered polymer-based composites. In this project, we focus on the polymer/liquid crystal (LC) system. The liquid-like LC microcapsules with the size of nanometer to sub-micrometer, liquid-like vinyl-functionalized nanosilica and alkyl-functionalized nanozirconia are initially synthesized based on the principle of molecular design, in-situ interfacial emulsion copolymerization and surface modification techniques. Then, they are introduced to the holographic polymer/LC system. During the visible-light-driven photopolymerization, the viscosity reduction effect of hyperbranched monomers, liquid-like components and LCs is expected to enhance the phase separation degree of the monomer/LC/inorganic nanoparticle composites. As a result, the complex of LC microcapsules, nanozirconia with high refractive index and LCs is located in the dark region of interference patterns to form the LC-rich phase, which can increase the refractive index modulation between the bright region and the dark one in the ordered polymer/LC gratings. Meanwhile, the vinyl-functionalized polyhedral oligomeric silsesquioxane (POSS) or silica nanoparticles whose refractive indices are similar to that of polymer are located in the bright region of interference patterns to form the polymer-rich phase, which is expected to decrease the volume shrinkage during photopolymerization. There are three main aims of this proposal. First, the synergistic effects of phase separation, volume shrinkage and refractive index modulation on microstructures and grating properties of the holographic polymer/LC/inorganic nanoparticle composites will be fully investigated. Secondly, we will develop novel applications of the storage of full-color three dimensional images and electric-optical responsive gratings based on these new holographic polymer/LC/inorganic nanoparticle composites. Finally, novel findings and conclusions of above research will advance the theory of ordered polymer-based composites, provide theoretical bases and new strategies for preparing high performance and functional ordered polymer-based composites.