Synthesis and characterization of porous and nonporous monodisperse colloidal TiO2 particles

Monodisperse spherical titania particles of variable sizes are produced in a sol-gel synthesis from Ti(EtO)(4) in ethanol with addition of a salt or a polymer solution. The influence of different salt ions or polymer molecules on the size and the size distribution of the final particles was investigated. The amorphous hydrous titania particles were characterized by electron microscopy, thermogravimetry, H-1-MAS NMR, X-ray absorption spectroscopy, and electrophoresis. Nitrogen absorption measurements revealed that the addition of polymers yields hollow and porous titania colloids.