Characterisation of TiO2 powders

The preparation with non-aqueous sol-gel techniques was in the focus for Nurse Avci from Ghent University in Belgium. He prepared with a team stable TiO2 sols by using two of the solgel processes with titanium n-butoxide and titanium isopropoxide, respectively. Crystallisation and phase transitions of powders and thin films were studied by ex situ and in situ X-ray diffraction. For both methods, TiO2 began to crystallise around 320° C in air. Using helium instead of air during heat treatment slowed down the crystallisation and substoichiometric powders were formed. TiO2 thin films were obtained by spin coating. The morphology of the films was evaluated using scanning electron microscopy. The films were homogeneous and transparent in the visible range. The effect of the heating atmosphere and the type of substrate was investigated. Please read more in the "Journal of Sol-Gel Science and Technology", Vol 52, pages 424-431.