Eco-friendly fabrication of robust superhydrophobic coating with excellent anti-corrosion and anti-icing properties through using submillimeter particles as protective structure

Abstract

Constructing superhydrophobic surfaces is a promising method for enhancing the anti-corrosion and anti-icing properties of metal materials. However, it is still a challenge to obtain robust superhydrophobic surfaces on metal substrate through simple and environmentally friendly methods. In this study, a robust superhydrophobic coating was fabricated on an aluminum substrate using a simple two-step method, i.e., sprinkling B₄C submillimeter particles onto the aluminum substrate coated with epoxy resin (EP) to construct submillitmeter protective structure, and then dipping a mixture of EP/polydimethylsiloxane (PDMS)/hydrophobic SiO₂ nanoparticles to impart superhydrophobicity. The mechanical robustness of the coating was evaluated using sandpaper abrasion, 3 M tape peeling, and sand impact tests. The results displayed that the coating maintained its superhydrophobicity after 16 m of sandpaper abrasion (3.2 kPa), 60 cycles of 3 M tape peeling, and 2500 g of sand impact, indicating the good resistance of the coating to different mechanical damages. The anti-corrosion property of the coating was measured by the electrochemistry tests, and the results confirmed that the coating possessed excellent anti-corrosion property with 34.06 times lower corrosion current density than the bare aluminum. The anti-icing property of the coating was assessed by freezing delayed time and de-icing force tests, and the results demonstrated that coating had outstanding anti-icing property with 730 s longer freezing delay time and 3–4-folds lower de-icing force than the bare aluminum. It can be excepted that the coating has a promising prospect in practical application due to its simple fabrication, good anti-corrosion and anti-icing properties and remarkable mechanical robustness.