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

Abstract 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 SiO 2 –TiO 2 sol and SiO 2 –TiO 2 -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 TiO 2 , the composite coating can restore the super-hydrophilicity damaged by dust under UV light.