Hydrophobic and optical properties of silica antireflective coating prepared via sol-gel method

A simple and low-cost process for the preparing of multifunctional coating is essential in practical applications. Here, alkali-catalyzed SiO₂ antireflection coating was first prepared by using the sol-gel method, the tetraethyl orthosilicate (TEOS) and ammonia (NH₃·H₂O) were used as a raw material and catalyst, respectively. Then, a layer of dimethyl silicone was sprayed on the surface of the as-prepared primary coating to obtain a bifunctional coating of antireflection and hydrophobicity simultaneously. The experimental results shown that the peak transmittance of the as-prepared bifunctional coating was 98.11% in the wavelength range of 300–1500 nm, while the water contact angle of the prepared coating was 140°, which was caused by the introduction of hydrophobic methyl groups of dimethyl silicone. Besides, the tape adhesion test and pencil scratch test results shown that the coatings have excellent mechanical robustness. Therefore, this work provides a practical strategy for the preparation of bifunctional coatings with antireflective and hydrophobic properties. (paper)