Features of the occurrence of electrochemical processes in contact of sodium chloride solutions with the surface of superhydrophobic coatings on titanium

A joint analysis of the results of electrochemical studies and the evolution of the parameters of a sodium chloride solution droplet in contact with the coating under test reveals the pattern of changes in the surface state which result from the electrochemical reactions and adsorption-desorption processes at the coating/electrolyte interface. Features of the corrosion process are studied on titanium samples with different protective layers on the surface: (1) a natural oxide, (2) a coating prepared via plasma electrolytic oxidation (PEO coating), (3) a PEO coating with a hydrophobic layer, and (4) a PEO coating with a superhydrophobic nanocomposite layer. The best protective properties in a chloride-containing electrolyte are exhibited by the superhydrophobic nanocomposite coating. The mechanism of corrosion protection of this coating is formulated.