Effect of Degussa P25 on the Morphology, Thickness and Crystallinity of Sol-Gel TiO_2 Coating

摘要

The deposition of titanium dioxide, TiO_2, films on various substrates was studied in order to take benefit of its antimicrobial properties for suitable application in related fields. In this paper, the effect of Degussa P25 (a commercial TiO_2 nanoparticles additive in the sol) on the morphology, thickness and crystallinity of the deposited TiO_2 was investigated. TiO_2 films, without and with Degussa P25, were deposited on glass slides and unglazed ceramic tiles via sol-gel process. Films were deposited ten times using dip coating technique and heat treated at 500℃ for 1 hour. The coating morphologies and thickness were analyzed using Scanning electron microscope (SEM), while the crystalline phases were characterized using Glancing angle X-ray Diffraction (GAXRD). Results show that the addition of Degussa P25 produces coating with homogeneous morphology and less cracks, thicker film and promotes the presence of anatase and rutile phases. It was also observed that the deposition of TiO_2 with Degussa P25 on unglazed ceramic tile produced thicker film (~120μm) as compared to the film deposited on glass slide (~7μm). Thus, it can be concluded that the addition of Degussa P25 affect the morphology, thickness and crystallinity of the TiO_2 coatings, whereas the type of substrate only affects the coating morphology and thickness, but not the crystallization of the TiO_2 coating.