Influence of Ph Value of Tio2 Sol on Surface Gloss of Corresponding Tio2 Film Coated on Ceramic Tiles

A series of TiO2 sols with different pH values prepared by the sol-gel method under acid conditions were coated onto the surfaces of ceramic tiles to obtain the corresponding TiO2 films respectively. The surface gloss and roughness of the as-prepared TiO2 films were measured by a glossmeter and an atomic force microscope (AFM) respectively. It has been found that the surface gloss of the as-prepared TiO2 films is decreased but its roughness is increased with the increase of the pH value of TiO2 sol. Moreover, the measurement result of the as-prepared TiO2 sols by Zetasizer shows that the ζ potential of TiO2 sol is increased with the increase of pH value of TiO2 sol. It is proposed that the increase of ζ potential will cause a stronger repulsion of particles in TiO2 sol, resulting in a rougher surface and then lower surface gloss of the corresponding TiO2 film.