New prospects in the application of superhydrophobic coatings and corrosion inhibitors

Abstract

Superhydrophobic (SHP) coatings provide a promising method for the corrosion protection of metals and alloys. However, the degradation of SHP properties of protective films, the presence of defects in them, or local corrosion of metals (sometimes even though the superhydrophobicity of most of the surface area is preserved) can significantly reduce their anticorrosion efficiency, especially in aqueous chloride-containing solutions. In this regard, the study of the regularities of the combined action of corrosion inhibitors (CIs) and thin protective SHP layers on metals is of great importance for the practice of anticorrosion protection. This combination method of protection can solve the problem of the durability of SHP and anticorrosive properties of ultrathin coatings and would expand the scope of their application. This article discusses a new effective method of corrosion protection of aluminum alloy 2024 in chloride-containing media based on the combined use of SHP coating and CIs (potassium dichromate, sodium molybdate and cerium(III) chloride). The realization of this method proves its effectiveness: the addition of Ce3+ (Cin = 1 mmol/l) increases 66-fold the protective ability and stability of the SHP coating of stearic acid in 0.5 M NaCl solution.