Rapid physical preparation of a superhydrophobic surface on copper foil without low-surface-energy materials coating

Abstract

A method is proposed to directly obtain superhydrophobic properties by depositing a coating made of candle soot upon the copper foil surface. The process to prepare a surface of superhydrophobicity is simple and rapid, which was performed just by placing the copper foil over the flame of a burned candle for no more than 10 minutes. The surface contact and slide angles of water were 159° ± 1.8° and 2°, respectively. Furthermore, the wettability on the copper surface of superhydrophobicity was also investigated. We found that the copper superhydrophobic surface prepared by the method had excellent superhydrophobicity for water; acid, alkali and salt solutions; and other liquids. In contrast to the traditional approach to prepare superhydrophobic surfaces, the method proposed in this study not only did not damage the mechanical properties of the substrate surface but also did not require low surface energy materials to be modified. This study provides a new approach for the protection of copper and other metallic materials.