Development of stable superhydrophobic coatings on aluminum surface for corrosion-resistant, self-cleaning, and anti-icing applications

Abstract Aluminum (Al) has been widely used in numerous applications, but it is prone to contamination or damage under harsh working environments. In this paper, a superhydrophobic coating (SHPC) on the Al surface was fabricated via a simple and cost effective method using anodization in sulfuric acid electrolyte followed by surface modification with inexpensive myristic acid. The as-prepared SHPC with hierarchical micro-nanostructure exhibited good superhydrophobicity with a static water contact angle (CA) of 155.2 ± 0.5° and a sliding angle (SA) of 3.5 ± 1.3°. The SHPC possessed both good mechanical and chemical stabilities: it retained a CA as high as 151.1 ± 0.1° after mechanical sandblasting for 60 s and was stable after dripping test using both acidic and alkaline solutions. Besides, after exposure to UV/water condensation cycles for 7 days, the coating remained superhydrophobic, indicating excellent weathering resistance. The prepared SHPC also demonstrated excellent self-cleaning and anti-icing performance. Ice adhesion strength as low as 0.065 ± 0.022 MPa was obtained for the optimized coating. Electrochemical measurement showed that there is a two-order of magnitude of reduction of the corrosion current density (J corr ) and the protection efficiency ( P %) of the as-prepared SHPC has reached up to 99.75%.