悬浮液气-液界面二元胶体颗粒的漂浮组装机理

提出一种在悬浮液气-液界面漂浮组装亚微米单分散聚苯乙烯(PS)微球和纳米SiO2颗粒二元胶粒晶体的新方法, 并系统研究了漂浮组装机理. 研究表明, 聚苯乙烯微球和二氧化硅两种胶体颗粒在悬浮液气-液界面的漂浮组装是以PS微球的组装为主导的. 在一定PS微球相浓度范围内, 悬浮液中PS 微球与SiO2颗粒的初始体积配比基本不影响PS微球有序组装的形成. PS微球粒径在150-500 nm时易于形成有序排列, 较小或较大粒径的PS微球难以形成有序排列. SiO2颗粒的组装是一种以PS微球为“基底”的沉积过程. 二元胶粒晶体中SiO2颗粒的体积分数由其在混合悬浮液中的相浓度所决定.

Mechanism of Floating Self-assembly of Binary Colloidal Particles at Water-Air Interface of Suspension

The floating self-assembly of submicron monodisperse polystyrene (PS) spheres and SiO_2 nanoparticles at water-air interface of suspension (floating assembly method) was presented in this article.The mechanism of this method was extensively studied.It was shown that the assembly of PS microspheres was dominant in the floating assembly of binary colloidal particles.At definite phase concentration,the formation of ordered structure of PS microspheres had nothing to do with the initial volume ratio of PS microspberes and SiO_2 nanoparticles in suspension.When the diameter of PS microspheres was in the range of 150-500 nm,the ordered structure could be obtained easily,otherwise it was difficult.The self-assembly of SiO_2 nanoparticles was a depositing process at the surface of PS microspheres as substrate.The volume fraction of SiO_2 particles in binary colloidal crystal was determined by the phase concentration of SiO_2 in suspension.