A simple immersion approach for fabricating superhydrophobic Mg alloy surfaces

A simple immersion approach for fabricating superhydrophobic Mg alloy surfaces is present here. Micro/nanometer-scale rough structures composed of micrometer-scale island-like rough structures and nanometer-scale sheets are generated on the Mg alloy surfaces after immersion in the aqueous CuSO4 solution. After ultrasonic cleaning, the micro/nanometer-scale rough structures are disappeared, whereas the lump-like rough structures appear on the Mg alloy surfaces. After modification with stearic acid, the as-prepared micro/nanometer-scale rough structures and the micrometer-scale lump-like rough structures all show superhydrophobicity. The contact angles of the water droplet on the aforementioned two structures are respectively 151.3° and 161.8°. The rolling angles are respectively 3° and 13°. The results indicate that the cooperation of suitable rough structures and stearic acid modification is responsible for the obtained superhydrophobicity on the Mg alloy surfaces.