聚苯乙烯-银胶体晶体的制备及自组装行为

Preparation of Polystyrene-Ag Latex Particles and Self-Assembly Behaviour of Colloidal Crystal

利用冠醚可与银离子复合的特性,制备了聚苯乙烯-冠醚乳胶粒,采用原位还原的方法在乳胶粒表面引入银纳米颗粒,通过垂直沉降,乳胶粒子可自组装成紧密堆积具有面心立方的聚苯乙烯-银胶体晶体。结果表明:引入聚苯乙烯-银乳胶粒表面的银为胶粒总质量的6.7%,乳胶粒具有以银纳米颗粒为壳,聚苯乙烯为核的核壳结构,乳胶粒大小为260 nm,并具有很好的单分散性。由于Bragg散射,该胶体晶带隙位于580 nm,在可见光区域产生明显的光子带隙而呈现出亮丽的绿色。

Crown ether was introduced to copolymerize with the monomer of styrene owing to which can associate with silver ions. The silver ions were in-situ reduced to silver nanoparticles by UV light. Then silver nanoparticles were led on the surface of polystyrene latex particles. The vertical precipitation was employed to get the spheres self-assembled into close packed colloidal crystal with a face centered cubic structure identified. Result indicates： The silver in the polystyrene-Ag latex particles is 6.7% （mass fraction）. The colloidal particle has core-shell structure and the diameter of the particle is about 260 nm with a remarkably monodisperse in size distribution. Due to Bragg scattering, The stop band of the colloidal crystal is located at 580 nm and the colloidal crystal shows iridescence with green colour.