Hydrophobic, organic–inorganic hybrid sol–gel coatings containing boehmite nanoparticles for metal corrosion protection

Abstract

In this study, fluoro-functionalized hydrophobic/oleophobic hybrid nanocomposite coatings, which are highly resistant and transparent, long-lasting and mechanically stable, have been deposited on metal substrate surfaces by the sol–gel method. Organic–inorganic hybrid matrix was prepared using tetraethoxysilane and organically modified silicon alkoxide, namely 3-(glycidyloxypropyl) trimethoxysilane. Additionally, to increase hydrophobic behavior, a fluorinated silica-alkoxide precursor and AlO(OH) NPs were added to the hybrid matrix. Water and n-hexadecane contact angle, surface morphologies, thicknesses and surface roughness of the films were determined. Additionally, optical characterizations and mechanical properties of the films such as light transmittance, haze, clarity, gloss were investigated. A salt spray corrosion test and electrochemical corrosion measurements were also performed. Optimum properties were acquired in the hydrophobic hybrid nanocomposite coating containing 15 wt% of 3 nm AlO(OH) NPs.