Preparation of scratch resistant superhydrophobic hybrid coatings by sol-gel process

Organic-inorganic hybrid coatings on glass substrates with superhydrophobic properties and with improved scratch resistance were obtained by means of applying a multilayer approach including multiple sol-gel processes. The coatings exhibited a water contact angle (WCA) higher than 150°. Ultraviolet (UV)-curable vinyl ester resins and vinyltriethoxysilane (VTEOS) as coupling agent were employed to increase the adhesion between substrate and the inorganic layers. The surfaces were characterized by means of dynamic contact angle and roughness measurements. Indeed, the occurrence of superhydrophobic behavior was observed. The scratch resistance of the hybrid coatings was tested to evaluate the adhesion of the coatings to the glass substrate. The proposed preparation method for scratch resistant, mechanically stable, superhydrophobic coatings is simple and can be applied on large areas of different kinds of substrates. © 2014 Elsevier B.V.