Double-layer anti-reflection coating of SiO2-TiO2/SiO2-TiO2-PEG300 with high transmittance and super-hydrophilicity

A highly transparent and super-hydrophilic double-layer anti-reflection coating was prepared by a simple and economical sol-gel method based on the glass substrate. The bottom and top layer were respectively made with SiO2-TiO(2)sol and SiO2-TiO2-PEG300 sol. The average transmittance of the substrate coated with the double-layer coating is increased by 7% up to 97.4% in the visible light band, and the peak transmittance reaches 99% at about 550 nm. In addition, double-layer anti-reflection coating shows a good super-hydrophilic self-cleaning performance, and the transmittance of the coating can be restored by simple washing with water. Furthermore, due to the existence of anatase TiO2, the composite coating can restore the super-hydrophilicity damaged by dust under UV light.