A simple and economic approach to superhydrophobic films

It has been recognized that a simple and economic preparation of superhydrophobic films is the prerequisite for their industrial and commercial applications. In this work, superhydrophobic films were successfully achieved on insulating materials. For such films, the contact angle can reach a maximum of 151.8° (sliding angle about 8°) with a surface roughness of 10.88 μm. If surface roughness was less than 10.88 μm, the contact angle increased with roughness, but for roughness greater than 10.88 μm, the contact angle decreased with roughness. It was further revealed that the surface hierarchical structures of the films were responsible for such a high contact angle and a low sliding angle. Moreover, the wetting ability of the rough films was different and can be interpreted using the different wetting state models. In addition, sandstorm tests and hydrophobicity experiments showed that such films could resist the external force well and exhibit a durable superhydrophobicity.