Spray-Deposition of an Organic/Inorganic Blend for Fabrication of a Superhydrophobic Surface: Effect of Admixing with Silica Aerogel and Modified Silica Nanoparticles

Superhydrophobic and self-cleaning glass slides were fabricated using a facile and low-cost method through spray-coating of four types of blends consisting of stearic acid, the mixture of stearic acid and SiO2 nanoparticles, the mixture of stearic acid and SiO2 nanoparticles modified with oleic acid, and the mixture of stearic acid and SiO2 aerogel onto the surface. The nanocoated surfaces were characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), and water contact angle (WCA) measurements. The results have shown that the mixture of stearic acid and SiO2 nanoparticles modified with oleic acid coating possessed the highest contact angle of about 158.6° and a low sliding angle while the mixture of stearic acid and SiO2 aerogel had an almost similar WCA but with a more satisfactory durability. In contrast, the stearic acid coating alone had a hydrophobic property and the mixture of stearic acid and unmodified SiO2 nanoparticles showed superhydrophobic properties without any self-cleaning and durability features.