Triethoxyoctylsilane-Modified SiO2 Nanoparticle-Based Superhydrophobic Coating for Corrosion Resistance of Mild Steel

In this work, SiO2 nanoparticles-based corrosion-resistant superhydrophobic coating for mild steel has been developed. A wire electrical discharge machine (EDM) was used to cut micro-patterned mild steel followed by chemical etching via Piranha solution. The etched metal was coated with triethoxyoctylsilane-modified SiO2 nanoparticles via the solution method to generate the hierarchical micro-nano roughness with low surface energy. The developed coating exhibited micro-nano hierarchical roughness due to SiO2 nanoparticles and their clusters, verified by atomic force microscope (AFM) and field-emission scanning electron microscope (FESEM) analysis. The maximum water contact angle (CA) of 153 ± 2° with a sliding angle (SA) of 5 ± 2° was obtained for the coated mild steel. The electrochemical impedance spectroscopy (EIS) plots confirmed the noteworthy corrosion resistance performance of coated metal over the uncoated one. Thus, the modified SiO2 nanoparticles-based superhydrophobic coating could be a good option for inhibiting the corrosion of mild steel.