PVDF surfaces with stable superhydrophobicity

Rough surfaces on pure polyvinylidene fluoride (PVDF) substrate were created via a simple roughening method using sandpaper. After modification with fluoroalkylsilane, the rough surface of PVDF exhibits superhydrophobicity, with contact angle larger than 160° and sliding angle lower than 5° not only for pure water but also for aqueous solutions under both acidic and basic conditions. In addition, the as-prepared surface possesses stable superhydrophobicity in various environments, such as ultrasonic cleaning, immersion in various organic solvents and inorganic aqueous solutions, temperature variation and UV irradiation. The stability of the low surface energy coating on the surface of PVDF was interpreted by the strong mechanical interlock interaction existing between the rough surface of PVDF and the continuous rough structures of the coating.