Formation and anticorrosion properties of superhydrophobic zinc coatings on steel

The work is dedicated to studying the possibility of formation of superhydrophobic zinc coatings on a steel support and estimating their protective ability and chemical state of the surface. Dendrite-like zinc structures are first obtained by potentiostatic electrodeposition from a sulfate-acetate solution with a low concentration of zinc ions and then treated by stearic acid. The influence of the zinc deposition potential on the deposit morphology, value of the wetting angle, and corrosion resistance of superhydrophobic coatings in a salt spray chamber is analyzed. The optimal mode of electrodeposition with respect to preservation of superhydrophobic properties of the deposits under exposure to a neutral salt spray is deposition at Ec = -1500 mV (vs. a Ag/AgCl electrode) for 1000 s. The average value of the wetting angle for such surfaces remains ≥151° after 148 h of the salt spray chamber treatment, up to the appearance of the first signs of the zinc coating corrosion damage. A positive effect of ultrasonic treatment of zinc-coated samples coated with stearic acid on the superhydrophobic properties is discovered.