Nanocrystalline titanium oxide thin films prepared by sol-gel process

Abstract

"Crystalline films of pure titanium oxide have been prepared on soda lime slide glasses by sol-gel processand dip-coating. The definition of various parameters such as chemical concentration, viscosity, catalyst typeand withdrawal speed led to the preparation of transparent, crystalline and adherent coatings with hydrophobiccharacteristics. Their crystalline structure was evaluated as anatase phase by low angle X-ray diffraction. Thicknesseswere measured by perfilometry, and the refractive indices were determined from transmittance spectrumtaking into consideration the layers deposited onto the two sides of the substrate. Porosity was also estimatedby UV-visible spectroscopy by using the Lorentz – Lorenz equation. The average grain size was evaluated byatomic force microscopy. The thicker and denser films presented hydrophobicity, which decreased when thefilm porosity increased."