电场诱导下非球形粒子的动态自组装及其光传输性质的研究

The ordered structures by assembly of colloidal particles have many novel properties and functions, and received increasing attention from researchers. But, the basic elements are often spherical particles. According to the theoretical calculations, it is impossible for the spherical particles to have a complete photonic band gap due to its symmetry. Using nospherical particles as basic element can avoid the above mentioned limitations. Meanwhile, an electric field as external forces should help us to achieve miniaturized devices. So, we will prepare nospherical particles by sol-gel method and study of the dynamic self assembly and optical properties of these particles.The surface potential, dielectric constants, refractive index and shape etc of these particles will be study under electric field, and their impact on optical properties will be precisely defined. The relationship of different novel order structures and light propagation features will be realized by using dynamic electric field and real-time observation. The research results will have an important value for to study further self assembly of colloidal particles and lay a foundation for the novel photonic devices.

组装成有序结构的胶体粒子可以获得多种新的特性和功能而受到关注，但组装基元多为球形粒子，理论研究表明球形在调整光学性质时有其局限性（很难获得完全带隙）。采用非球形粒子进行自组装具有获得更多新颖结构和性能的潜力，电场易于调控和集成，在元器件小型化时具有优势。故研究电场调控非球形粒子自组装在理论和实验方面均具有重要意义。目前，研究者更侧重于非球形粒子结构演变的观察或理论推导，而对与其相对应的光传输性质的实验研究还有待于完善。因此，本课题组拟通过sol-gel法和溶剂热法制备非球形胶体粒子，然后以其为研究体系，深入研究电场调控下非球形粒子自组装结构的光调变行为，获得粒子物性参数和电场参数对自组装结构和光学性质的影响，并提出相应机制。探讨电场下形状各异粒子自组装结构对色彩控制的影响，揭示胶体自组装微观结构和宏观光学性质之间的联系，为设计开发新型光电器件奠定基础。

组装成有序结构的胶体粒子可以获得多种新的特性和功能而受到关注，通过外界刺激驱动胶体颗粒悬浮液形成有序的排列，获得可逆、可调的响应性光子晶体(RPCs)，从而调控胶体晶结构的各种性能的研究成为热点。本项目组采取溶剂热法制备了球形，纺锤形，棒状等多种胶体粒子（像氧化硅、三氧化二铁，四氧化三铁，C球等），然后以其为研究体系，采用电场调控的方法系统研究了颗粒的尺寸、形貌、悬浮液浓度、分散剂与反射光谱之间的关系，同时研究了介电性质和电场响应的时间。深入研究电场调控下各种粒子自组装结构的光调变行为，获得了粒子物性参数和电场参数对自组装结构和光学性质的影响，并提出相应的粒子受力机制，揭示胶体自组装微观结构和宏观光学性质之间的联系，为设计开发新型光电器件奠定基础。