title: Close-packed colloidal crystalline arrays composed of polystyrene latex coated with titania nanosheets.
abstract: We have demonstrated that polystyrene latex coated with titania nanosheets can be fabricated into a close-packed colloidal crystalline array, and that these coated colloidal spheres can be used to control the peak position of optical stop bands through the coating. The titania-nanosheets-coated polystyrene latex was prepared by the layer-by-layer (LBL) assembly coating process, involving alternating lamination of cationic polyelectrolytes and anionic titania nanosheets on monodisperse polystyrene latex particles. The Bragg diffraction peak of the colloidal crystalline array shifted to longer wavelengths with the coating of titania nanosheets. This red shift was caused by an increase in refractive index upon coating, as revealed by angle-resolved reflection spectra measurements. The current work suggests new possibilities for the creation of advanced colloidal crystals having tunable optical properties from tailored colloidal spheres.
authors.affiliation: Toyota Central Research & Development Laboratories, Inc. Aichi, Japan. nakamura@mosk.tytlabs.co.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakamura
authors.forename: Masahiko
authors.initials: M
authors.lastname: Ishii
authors.forename: Azusa
authors.initials: A
authors.lastname: Tsukigase
authors.forename: Masashi
authors.initials: M
authors.lastname: Harada
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Nakano