Fabrication of hierarchical superhydrophobic surfaces

The hierarchical rough structure is essential for superhydrophobic surfaces. In this paper, we prepared a hierarchical surface composed of micro-dot-matrix and SiO₂ nano porous network. The micro-dot-matrix was fabricated on the glass substrate by photolithography and ion beam etching. The SiO₂ nano porous network was generated by incompletely combustion of hexamethyl disilazane (HMDS) and deposited on the surface of substrate via dip-coating. Owing to the incompletely combustion of HMDS, the methyl group was still existed and the resultant surface with hierarchical structure exhibits excellent superhydrophobic property with water contact angle of 157° and water sliding angle of 2° without further low-surface-energy modification. Our method is facile, convenient and scalable which provides a promising avenue for large-scale production.