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.

Study on PS/TiO2 nanocomposite particles

“…In this family, the hollow TiO 2 spheres have attracted considerable interest owing to their applications in catalysis, photochemical solar cells, controlled release, chemical sensors and so on. [1][2][3][4] The polystyrene/titanium dioxide (PS/TiO 2 ) core shell spheres are prepared in two main approaches: layer-by-layer self-assembly 5 and sol-gel nanocoating. [6][7][8][9] The sol-gel nanocoating is widely used due to its simplicity and high efficiency.…”

Fabrication of hydroxyl group modified monodispersed hybrid silica particles and the h-SiO2/TiO2 core/shell microspheres as high performance photocatalyst for dye degradation

“…Titania-shell composite particles are prepared by sol-gel processes [2][3][4], or coating of titania nanoparticles onto the silica or polymer microspheres through the layer-by-layer (LBL) technique [3,7]. Although the LBL technique shows good control on the size and uniformity of the resulting particles, the LBL method is more tedious with long synthetic steps.…”

Rayleigh like scattering from silica–titania core-shell particles and their application in protection against harmful ultraviolet rays

“…The composite particles having silica core and titania shell are widely studied. These particles are typically synthesized using techniques like layer-by-layer deposition (Caruso et al 1999(Caruso et al , 2001Nakamura et al 2005Nakamura et al , 2006, sol-gel synthesis (Holgado et al 2000;Guo et al 2003;Kim et al 2003;Liu et al 2005;El-Toni et al 2006;Lim et al 2008), laser pyrolysis (Maskrot et al 2006), heterocoagulation (Wilhelm and Stephen 2006) and flame synthesis (Hu et al 2007). Most of these methods involve multiple steps, pH control and ingredients like surfactant polyelectrolytes which makes it difficult to replicate in bulk scale.…”