Preparation of PS@SiO2, PS@TiO2，PS@TiO2/SiO2 Core-Shell Composites by a Spray Drying Process and Their Hollow Spheres after Removing PS Cores by Calcinations
Polystyrene (PS) spheres encapsulated core-shell composites of SiO2 or TiO2 nanoparticles were prepared by the spray drying technique and hollow spheres of SiO2 or TiO2 nanoparticles were then derived by removing the PS cores with calcinations. The PS spheres were dispersed into the SiO2 or TiO2 colloids, forming a suspension and then the suspensions were sprayed to form micrometer-sized droplets, as the droplets rush through the drying chamber, the PS spheres were encapsulated into the core of SiO2 or TiO2 particles due to the high temperatures and the instant evaporation, obtaining PS@SiO2, PS@TiO2 or PS@SiO2/TiO2 core-shell composites. After removing the PS core by calcination at 550°C, SiO2 or TiO2 hollow spheres were then derived. The influence of drying temperature, the concentration of the SiO2 or TiO2 particles and the ratio of PS sphere to the particles on the structures and specific surface area of the hollow spheres were studied with scanning electron microscopy (SEM) and nitrogen adsorption-desorption measurements.
Jianmin Zeng, Taosen Li, Shaojian Ma, Zhengyi Jiang and Daoguo Yang
L. Li et al., "Preparation of PS@SiO2, PS@TiO2，PS@TiO2/SiO2 Core-Shell Composites by a Spray Drying Process and Their Hollow Spheres after Removing PS Cores by Calcinations", Advanced Materials Research, Vols. 194-196, pp. 389-392, 2011