Enhancement of mechanical robustness and anti-icing property of superhydrophobic coating through introducing interlock effect and high-aspect-ratio micro-scale structure using chemical etching method

Superhydrophobic coatings have been considered as promising candidates for anti-icing application in recent years. However, such coatings are easily damaged by mechanical loads due to their fragile micro/nano structures, and they are also prone to transit from the Cassie-Baxter to the Wenzel state during icing process, which greatly limits their lifespan. Herein, a superhydrophobic coating with a water contact angle of 152.5° and water sliding angle of 4° was prepared on aluminum substrate through chemical etching followed by spinning. The coating possesses high-aspect-ratio micro-protrusions and strong interlock with substrate, thereby endowing it with larger energy barrier for water impaling in rough structure, smaller heat losses with freezing droplet, superior protecting effect for nanostructure. Consequently, the coating exhibits enhanced anti-icing and mechanical robustness with a ~7.7-fold prolongation in freezing delay than the bare Al substrate and superior withstanding capacity in a series of tests. It can be expected that the coating has a promising prospect in the practical anti-icing applications owing to its straightforward fabrication, good mechanical robustness and excellent anti-icing property.