Environmentally-friendly superhydrophobic surface based on Al2O3@KH560@SiO2 electrokinetic nanoparticle for long-term anti-corrosion in sea water

Superhydrophobic surface has aroused wide concern over the years due to its extensive application prospect. However, a simple, cost-effective and environmental friendly preparation method is still lacking. Here, we present an effective approach to prepare a superhydrophobic surface for long-term metal corrosion protection. Positively charged SiO2 composite nanoparticles were successfully prepared by a simple and multiple ultrafiltration method firstly, after that the particles were sol-gel electrodeposited on steel to build micro-nano roughness surface, and then the surface was modified by cost-effective and fluorine-free chemical stearic acid with low energy surface. The results of wettability experiment show a strong repulsive force between the modified surfaces and water droplets, with static contact angles over 158 degrees. The corrosion resistance and corrosion current density of the Al2O3@KH560@SiO2 composite film assessed by the electrochemical impedance spectroscopy (EIS) and the polarization and neutral salt spray test indicate that the corrosion rate of the metal is reduced and the corrosion performance of the matrix is improved at the same time.