Fabrication of Superhydrophobic Surface on Magnesium Substrate by Chemical Etching

Superhydrophobic surfaces are attractive because of their special wettability properties. In recent years, artificial superhydrophobic surfaces have been studied extensively because of the demand for self-cleaning materials.1-6 The contact angle of water on a clean surface is a measure of its hydrophobicity. A water contact angle larger than 150 ° and a sliding angle less than 10 ° are the key characteristics of superhydrophobic surfaces. The wettability of a surface is controlled by its surface structure and chemical properties. In nature, many species demonstrate superhydrophobicity (e.g., lotus leaves and spiders).7-11 The self-cleaning pro-perties of lotus leaves are based on its papillae structure and wax coating. Coating a solid with a low surface energy material increases the water contact angle however; the contact angle of a flat surface generally does not excee