Controllable preparation of quasi-monodispersed spherical titania particles

Quasi-monodispersed spherical titania particles with variable sizes were prepared by the sol-gel synthesis with the addition of surfactant. The particles were characterized by the scanning electron microscope, transmission electron microscope, X-ray diffraction and nitrogen absorption. The influence of surfactant of ODA, Span-80, F-127 and PEG with various molecular weight on the morphology, the size, and the size distribution of particles was investigated respectively. The research results show that the steric hindrance of surfactant is very important to morphology, size and size distribution of titania particles. Perfect spherical particles can be obtained when the steric hindrance of surfactant is big enough. Nitrogen absorption measurements reveal that titania particles synthesized by addition of F-127 or PEG-20000 possess meso-pore structure, and the pore diameter is about 3.4 nm and 2.6 nm, respectively.