Self-assembled colloidal crystalline arrays using hollow colloidal spheres

Well-defined mesoporous colloidal crystals are generally prepared using templates, but these procedures are often very complicated. In this paper, we report a simple one-step method for forming three-dimensionally (3-D) ordered mesoporous polymer colloidal crystalline arrays (CCA). The CCA were formed by self-assembly of monodispersed hollow colloidal spheres obtained by classification of polydispersed hollow colloidal spheres in gravitational field, combined with separation using membrane technology. Four different methods have been employed to self-assemble polymer colloidal crystals, which were then experimentally evaluated. The polymer CCA formed by this method should be useful for preparing photonic band-gap materials and other applications.