Fabrication of antireflective coatings with self-cleaning function using Si–Ti modified hollow silicon mixed sol

Abstract

The antireflective coating (ARC) is fabricated by the sol-gel method using mixed sol modified by Si–Ti composite sol. The effects of the mixing ratio of Si–Ti composite sol and hollow silica sol on the surface morphology, optical properties, mechanical properties, and wetting ability of the ARC were studied. Moreover, the self-cleaning ability and environmental stability were examined via dip coating the modified sol on glass substrates. The proposed ARC exhibited a total solar-weighted transmittance (Тsw) of more than 94.97% over a wavelength range of 380–1100 nm, significantly higher than that of the bare glass substrate (Тsw = 90.62%). After modification, the proposed ARC exhibited a hardness of 3 H. In addition, the coating presented an extremely hydrophilic surface with a minimum water contact angle of less than 5°. Water droplets resulted in the formation of a water film on the ARC surface, which could significantly reduce the adverse effects of subsequent pollutants on the coating transmittance; simultaneously, owing to the introduction of TiO2, the coating could oxidatively decompose organic contamination. Finally, damp test results showed that the ARC transmittance only decreased by 0.05%, indicating good environmental stability.