胶体晶体自组装排列进展

Fabrication of Colloidal Crystal Array by Self-Assembly Methods

自组装排列胶体晶体是发展光子晶体等亚微米周期有序结构及新型光电子器件十分重要的环节。高电荷密度单分散胶体球在较弱的离子强度和稀浓度下会自发排列形成紧密堆积的周期性结构 (ccp) ,常常是面心立方 (fcc) ,科学家们以此为基础发展了多种结晶化胶体粒子的方法 ,包括重力场沉积、电泳沉积、胶体外延技术、垂直沉积、流通池、物理束缚排列及其他的许多方法。目前排列的胶体粒子基本为球形 ,材料也多为SiO2 、PS、PMMA ,此外一些复合粒子 ,主要为核壳粒子的排列这里也稍作介绍 ,这些方法及其变通的使用可以形成类蛋白石及反蛋白石结构 ,最终实现光子带隙及其它多种用途。

Self-assembly of colloidal crystals has been a key procedure in developing sub-micron periodic and ordered structures such as photonic crystal, and other unique optoelectric devices. Considering that highly charged monodisperse colloidal spheres with a low concentration can spontaneously organize themselves into ccp crystalline arrays, mainly fcc structures, under weak ionic strength, scientists have developed a variety of approaches to crystallize colloidal particles, including gravitational sedimentation, electrophoresis, colloidal epitaxy, vertical deposition, flow cell with physical confinement and so on. Most used colloidal particles are spherical silica, PS, PMMA colloids. Also we report composite particles, most of which are core-shell particles. With these methods and their modifications the opal and inverse opal structures could be obtained and photonic band gap and other applications be realized.