Transparent and Self‐Cleaning Surfaces Based on Nanocomposite Sol‐Gel Coatings

Abstract

AbstractIn this study, transparent anti‐fogging and self‐cleaning nanocomposite coatings based on sponge‐like TiO2−SiO2 nanoparticles on glass substrate were prepared through the sol‐gel process, by using spin‐coating and spray gun techniques to coat small and large glass surfaces. The effect of annealing temperature on the morphology, wettability, UV–Vis transmittance, refractive index, thickness, photocatalytic degradation rate and the anti‐fouling effect was studied in detail. Indeed, the self‐cleaning properties of the nanocomposite coatings were evaluated as efficient by both photocatalytic degradation of orange G (OG) dye under natural sunlight irradiation and water contact angle (WCA) method under atmospheric out‐door conditions. It should be noted that the optical transmission of nanocomposite coatings remains important (85–87 %) compared to the ordinary glass (92 %) with lower haze value, which confirms their clear optical appearance. The nanocomposite coatings rendered the glass substrate hydrophilic with a WCA value that not exceeding 12° after fifteen weeks of out‐door exposure. Photocatalytic degradation rate relative to OG up to 7.9 % were achieved for the nanocomposite coating annealed at 500 °C after 8 hours of sunlight exposition. The soil attachment test reveal that nanocomposite coatings prevent the accumulation of soil particles and has an excellent anti‐fouling and anti‐fogging properties. These findings indicated that the TiO2‐SiO2 nanocomposite coatings could be a very attractive solution for many practical areas (environment, energy and building sectors) especially for outdoor applications.