Ultra low water adhesive metal surface for enhanced corrosion protection

A superhydrophobic surface with ultra low water adhesive force is fabricated on various metals for enhanced corrosion protection. The superhydrophobic surface is constructed by passivated zinc oxide (ZnO) and low surface energy poly(dimethylsiloxane) (PDMS). The process of wettability transformation and corrosion are evaluated by a salt spray test and electrochemical measurement. The superhydrophobic surface is separated layer-by-layer to reveal the function of each layer in corrosion protection. The surface adhesive force is applied as a novel metric for precisely determining the wettability state on the substrate surface. The results reveal that the ultra low water adhesive force of the superhydrophobic surface can effectively suppress water condensation on the metal surface which can suppress the transformation from the Cassie to Wenzel state. The superhydrophobic surface can effectively inhibit corrosion because of the synergistic effect of the triple layered protection system of air, PDMS and ZnO.