Combination of chemical etching and electrophoretic deposition for the fabrication of multi-scale superhydrophobic Al films

In this study, we reported a new method to fabricate superhydrophobic Al films by combination of HCl/H2O2 etching and electrophoretic deposition process. Through this two-step method, multi-scale hierarchical structures were successfully introduced on the surface. After hydrophobization, the resultant surface showed an excellent superhydrophobicity with a water contact angle of 169.6° and a sliding angle of ca. 1°. Furthermore, the surface exhibited excellent mechanical durability and could withstand abrasion tests under 8 kPa for 60 cm without losing superhydrophobicity. It also maintained superhydrophobicity when exposed to air or water for a long-term period. This work provides a cost efficient method to prepare mechanically robust and stable superhydrophobic Al alloy surface.