Uniform Corrosion-Driven Electrochemical Engineering of Rose Petal Effect Superhydrophobic Aluminum Surfaces

A simple, fluorine-free strategy is proposed for engineering rose petal effect superhydrophobic aluminum surfaces through controlled electrochemical surface evolution. Unlike conventional fabrication methods based on aggressive chemical etching or low-surface-energy coatings, the proposed approach exploits electrochemically assisted corrosion within a carefully selected potential–current density window to generate a hierarchical micro/nanostructure while avoiding localized pitting. The textured surface is subsequently functionalized through a hot aqueous household sodium soap treatment, providing a low-cost and environmentally benign alternative to conventional fluorinated modifiers. Under the optimum processing conditions (0.5 A, 6.494 A dm−2, 2.5–2.4 V), the resulting surface exhibits a water contact angle of 155° ± 2° together with the characteristic high-adhesion rose petal effect. Microstructural observations indicate that the combination of electrochemically assisted etching and soap-assisted surface modification produces a hierarchical architecture capable of stabilizing the Cassie-impregnation wetting state responsible for simultaneous high-water repellency and strong droplet adhesion. The proposed protocol provides an energy-efficient, scalable, and environmentally friendly route for tailoring functional aluminum surfaces, offering promising opportunities for droplet manipulation, digital microfluidics, lab-on-chip devices, controlled condensation, and surface-energy engineering.