Hydrophobic fumed silica/epoxy coating: The impact of solvents on its hydrophobicity and durability

In this study, the effect of the solvents on the formation of superhydrophobic fumed silica/ FAS-17/epoxy surfaces modified by the incorporation of hydrophobic fumed silica nanoparticles was investigated. We used three different solvents, namely n-butyl acetate, ethyl acetate, and dichloromethane, to develop a superhydrophobic surface using the easily applicable doctor's blade method. Surfaces obtained were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR). The performances of the different solventbased coated surfaces were compared by measuring the contact angle (CA) of three liquids, sliding angles (SA), surface friction force, environmental adaptability, and self-cleaning performance. The water contact angles (WCAs) of the n-butyl acetate, ethyl acetate, and dichloromethane-based coated surfaces were 149.70 degrees f 5.52 degrees, 146.89 degrees f 3.7 degrees, and 147.34 degrees f 2.50 degrees, respectively, which were 150.36 degrees f 4.03 degrees, 147.53 degrees f 4.97 degrees, and 148.68 degrees f 3.36 degrees for a 3.5% NaCl solution. Comparing the wettability, environmental durability, and self-cleaning performance of the different solvent-based coated surfaces, n-butyl-acetate-based coated surfaces showed better performance compared to ethyl-acetate- or dichloromethane-based coated surfaces.