Preparation of Superhydrophobic Magnesium Alloy Surface via Fabrication of Micro/Nano Binary Structure and Modification with Perfluropolysilane

A three-step approach was employed to fabricating superhydrophobic magnesium alloy surface. Microstructure was first introduced on magnesium alloy substrate via a micro-arc oxidation technique. Subsequently, nanometric structure of micro-arc oxidation surfaces was prepared by coating epoxy acetone solution and silica suspension. Finally, perfluoropolysilane was deposited on these surfaces by nanocoating technology through a self-assembly route to form superhydrophobic magnesium alloy surface. The morphology, wettability and phase of surfaces were characterized by using scanning electron microscope, X-ray diffractometer, contact angle meter and high speed camera system. The results show that the micro/nano binary structure plays a great role in enhancing the hydrophobicity of surfaces. With increasing silica suspension concentration, surface contact angle first increases to reach maximum value of 161.2° at a silica concentration of 15.0 g/L and then decreases to 150.1° and levels off thereafter. In addition, the as-prepared superhydrophobic surfaces show a great characteristic of low adhesion, i.e., water droplet can roll easily on these surfaces.