Mechanochemical stable superhydrophobic coating toward lasting corrosion protection

Abstract

Superhydrophobic coatings are vulnerable to protection failures in long-term practical applications due to the decomposition of low surface energy materials and destruction of rough structures. In this work, a self-healing dual-layer polydimethylsiloxane/superhydrophobic coating was constructed on the Al alloy toward corrosion protection. The coating with a water contact angle of 151 ± 2.4° exhibits excellent low water adhesion, self-cleaning, and antifouling properties. The lowest-frequency resistance modulus of dual-layer superhydrophobic coating increases by two orders of magnitude compared with that of single superhydrophobic coating. Moreover, the coating still maintains superhydrophobicity under high/low temperatures (0–100 °C), acid/alkaline solution (pH = 1–14), drastic ultraviolet radiation (7 days), and mechanical wear (1600 cm). More importantly, the coating restores its superhydrophobicity several times after even in the face of extreme corrosive environments due to heating-driven migration of hydrophobic surfactants. Hence, the prepared self-healing superhydrophobic coating with mechanochemical stabilization has a bright prospect for anti-corrosion application under harsh service environments.