A fluorine-free superhydrophobic silicone rubber surface has excellent self-cleaning and bouncing properties

Superhydrophobic materials have been widely applied in self-cleaning, anti-fouling, anti-corrosion, anti-freezing. However, simple, efficient, environmentally friendly and large-area preparation is still a great challenge in the field of fabrication of superhydrophobic surfaces. In this paper, a simple physical deposition method is adopted to deposit a layer of alumina oxide (Al₂O₃) particles on the surface of the room temperature vulcanized (RTV) silicone rubber, and remove the excess Al₂O₃ particles on the surface to obtain the superhydrophobic surface of Al₂O₃/RTV silicone rubber. The contact angle and rolling angle of the superhydrophobic surface are 156.6° ± 1.1° and 5.1° ± 0.7°, respectively. It is found that the surface roughness of RTV silicone rubber is significantly increased via Al₂O₃ particles. The analysis of scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) demonstrate that the superhydrophobic surface is obtained via constructing rough structure of Al₂O₃ particles on the RTV silicone rubber surface. In addition, the self-cleaning and droplet bounce tests under different conditions show that the as-prepared superhydrophobic surface has remarkable self-cleaning and droplet bounce properties. Therefore, this method can be employed to simply and effectively fabricate superhydrophobic surfaces in large scale.