Shape Control of Colloidal Crystals for 3D Photonic Crystals

Abstract

Ordered macroporous particles of silica and titania were fabricated by colloidal templating. The colloidal templates were assembled through colloidal crystallization of polystyrene latex spheres suspended in aqueous droplets stradding at air-oil interface. The procedures involve first preparing spherical colloidal crystalline particles of polystyrene latex spheres. and then infusing them with metal precursor solution that form silica or titania the interstices. Finally, calcination decomposes the polystyrene latex spheres leaving behind macropores at their sites. The shape of template was controlled by the presence of additive surfactant or by the action of applied electric field. Specifically, spherial, concaved disk-like, and ellipsoidal colloidal crystals were prepared successfully and used as templates for the fabrication of ordered macroporous particles. The SEM images of the prepared macroporous particles showed that the pores were interconnected and ordered into a hexagonal arrangement.