Superhydrophobicity of polytetrafluoroethylene thin film fabricated by pulsed laser deposition

Abstract Superhydrophobic polytetrafluoroethylene (PTFE) thin films were obtained by pulsed laser deposition (PLD) technique carried out with KrF excimer laser ( λ  = 248 nm) of about 1 J/cm 2 at a pressure of 1.33 Pa. The samples exhibit high water contact angle of about 170° and the sliding angle smaller than 2°. From studying the surface morphology of the prepared films, it is believed that the nano-scale surface roughness has enhanced the hydrophobic property of the PTFE. The increase of trapping air and reducing liquid–solid contact area due to the rough surface, as suggested by the Cassie-Baxter's model, should be responsible for superhydrophobicity of the PLD prepared films. This study thus provides a convenient one-step method without using wet-process to produce a superhydrophobic surface with good self-cleaning properties.