Robust Rare‐Earth‐Containing Superhydrophobic Coatings for Strong Protection of Magnesium and Aluminum Alloys

Abstract

AbstractThe robust rare‐earth‐containing superhydrophobic coatings are fabricated by a simple and scalable method, which includes spraying the lanthanum hydroxide sol onto metallic substrates (AZ61 Mg and 2024 Al) and then modifying the surfaces with stearic acid. The as‐prepared coatings on AZ61 Mg and 2024 Al have identical morphology and composition. Both are composed of fiber‐like La(OH)3 nanowires that cross‐link and form a network structure, which are pivotal for inducing surface superhydrophobicity with water contact angles (WCAs) as high as ≈157°. The superhydrophobic coatings demonstrate remarkable corrosion resistance as well as high chemical and mechanical stabilities. The theoretical simulation based on molecular mechanics suggests that the high stabilities mainly arise from the strong bonding between La2O3 and stearic acid molecules. The fabrication approach proposed here is hopeful to extend for large‐scale preparation of robust superhydrophobic metallic materials widely applied.