Calcia-doped ceria is of potential interest as an ultraviolet (UV) radiation blocking material in personal care products because of its excellent UV light absorption property and low catalytic ability for the oxidation of organic materials superior to undoped ceria. The performance of calcia doped ceria needs more enhancement through further control of its oxidation catalytic activity and improvement of its covering ability. In order to reduce the oxidation catalytic activity further, calcia-doped ceria was coated with amorphous silica by means of seeded polymerization technique. Generally, nanoparticles of calcia doped ceria do not provide a good coverage for human skin because of the agglomeration of the nanoparticles. The platy particles are required to enhance the covering ability of calcia doped ceria. This can be accomplished by synthesis of calcia-doped ceria/plate-like material (e.g., potassium lithium titanate (K0.8Li0.27Ti1.73O4) and mica) nanocomposite with subsequent silica coating. Calcia-doped ceria/plate-like material was prepared by soft chemical method followed by silica coating via seeded polymerization technique. Silica coated calcia-doped ceria/plate-like material nanocomposite was characterized by X-ray diffraction, SEM, TEM, XPS and FT-IR.
