Water-repellant properties of mixed films with TiO2 base

This report is focused on the water-repellant properties of TiO2 and its mixed films with adding certain oxides or fluorides. It is well known that TiO2 films and powders can be used as a water splitting coating due to its photocatalytic reaction. With the addition of the second material, the absorption band and the microstructure of TiO2 films are changed, which will influence their photocatalytic properties. Mixed films based on TiO2 with various compositions were deposited on unheated BK7 glass substrates by e-beam gun coevaporation technique with ion bombardments. Some of the films were also deposited at a glass substrate temperature of 300 degree(s)C without ion assistance. The degrees of water repellence of these films before and after UV irradiation were evaluated in terms of the contact angle of the deionized water on the coating surface. The correlation between the composition, UV-light exposure time and the water-repellant properties of the mixed films ere evaluated and discussed.