CHEMICAL AND MICROSTRUCTURAL PROPERTIES OF TIO2 SYNTHESIZED BY SOL-GEL PROCEDURE

Nanosized TiO2 powders were prepared using the sol-gel procedure. The selected colloidal suspensions were stabilized with polyethylene glyco l (PEG). This polymer prevented sintering of TiO2 particles during the calcination of the starting material. X-ray powder diffraction (XRD) phase analysis showed that the samples, obtained up to 500 degrees C, were a mixture of anatase and brookite. In the samples, obtained at 85 0 degrees C and higher temperatures, rutile as a single phase was dete cted. The TGA/DTA curves were dependent on the preparation of TiO2 sam ples. The samples were also characterized by Fourier transform infrare d spectroscopy and laser Raman spectroscopy. A new method, based on lo w-frequency Raman scattering, was proposed for the size determination of nanosized TiO2. The size determination of nanosized TiO2 by low-fre quency Raman scattering was in a good agreement with crystallite size values obtained by XRD. (C) 1997 Elsevier Science S.A.