title: Fabrication of well-ordered binary colloidal crystals with extended size ratios for broadband reflectance.
abstract: Binary colloidal crystals (BCCs) possess great potentials in tuning material properties by controlling the size ratio of small to large colloidal spheres (γS/L). In this paper, we present a method for the fabrication of BCCs with much more extended size ratios than those obtained in conventional convective self-assembly method. It is found that γS/L can be extended to 0.376 by adding TEOS sol into the colloidal suspension. The resulting polystyrene/silica (PS/SiO2) BCCs show distinctive reflections, indicating their well-ordered structure. The extended size ratios render more flexibility in engineering the photonic bandgap structures of BCCs and hence provide a better platform for developing a range of applications such as photonics, spintronics, sensing and bioseparation.
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore , 4 Engineering Drive 4, Singapore 117576.
authors.forename: Zhongyu
authors.initials: Z
authors.lastname: Cai
authors.forename: Yan Jun
authors.initials: YJ
authors.lastname: Liu
authors.forename: Xianmao
authors.initials: X
authors.lastname: Lu
authors.forename: Jinghua
authors.initials: J
authors.lastname: Teng
mesh_terms: D003102:Colloids / Q000737:chemistry*; D003460:Crystallization
chemical_list: D003102:Colloids