Self Cleaning Photoactive TiO_2 Coatings on SLS Glasses by Sol-Gel Dip Coating

摘要

Self-cleaning and anti-fogging coatings can be realized utilizing TiO_2 thin films on various substrates. Photoactive TiO_2 films exhibit strong oxidation power to breakdown organic compounds when illuminated by UV. TiO_2 thin films possess photo-induced hydrophilicity, which is required for self-cleaning properties. They give optical quality with high reflectivity when coated on glass. In the present study, commercial float glass samples were coated by using sol-gel dip-coating process. Coated glasses were heat treated at 400 ℃ for obtaining the desired properties. In order to monitor the photoactivity of the films, the decrease in the absorption of the aqueous solution of rhodamine B was measured after light irradiation of film surfaces as a function of time. The photoactivity of the films was measured also through the decomposition of stearic acid applied onto TiO_2 films. In this study, the effects of film thickness and mean crystallite size on the photoactivity were given and discussed.