Monodisperse SiO_2/TiO_2 Core-shell Colloidal Spheres:Synthesis and Ordered Self-assembling

摘要

Monodisperse SiO_2/TiO_2 core-shell spheres have been prepared with conventional sol-gel method.The thickness of titania coatings on SiO_2 spheres was 30 nm,corresponding to 56.48 wt% titania loading and 1.66 effective refractive index of the composite particles.The relative standard deviation of composite spheres diameters distribution is 3.79%.The composite spheres were assembled,by gravity sedimentation,into three-dimensionally ordered colloidal crystals,which showed photonic band gap determined by UV-vis transmission spectrum.