Fabrication of superhydrophobic micro-nanostructured aluminum alloy surface via a cost-effective processing using an ultra-low concentration of fluoroalkylsilane

Abstract

Herein, superhydrophobic 4037 aluminum alloy surface with self-cleaning and anti-icing properties has been fabricated by a low-cost processing consisting of HCl/H2O2 treatment and modification of an ultra-low concentration of fluoroalkylsilane. Via a chemical etching, a coral-like hierarchical micro-nano structure has been formed on 4037 aluminum alloy substrate. Then, the wettability of etched surface treated with different levels of fluoroalkylsilane has been investigated. The results show that the etched surface after been modified with petroleum ether containing 20 mg fluoroalkylsilane can result in superhydrophobicity with a water contact angle of 160.8° and a sliding angle of 2.4°. Especially, effects of solvents on the wettability of fabricated surface have also been studied. It is found that alkane such as petroleum ether is suitably used as a solvent for fluoroalkylsilane due to a reduction on fluoroalkylsilane. In addition, obvious self-cleaning and anti-icing behaviors of the as-prepared superhydrophobic surface have been proved, which will extend the further application of aluminum alloy.