Fabrication of anisotropic PTFE superhydrophobic surfaces using laser microprocessing and their self-cleaning and anti-icing behavior

Due to excellent stability and intrinsic low surface energy, polytetrafluoroethylene(PTFE) is widely utilized to fabricate biomimetic superhydrophobic surfaces. We proposed a facile and rapid method to obtain outstanding superhydrophobic surfaces by CO2 laser microprocessing PTFE plate. Scanning electron microscope(SEM) and contact angle measuring instrument were employed to characterize the structure and wettability. The effects of different micro channels spacing, different processing times and different processing power on wettability and morphology were studied. The self-cleaning and anti-icing properties of the prepared PTFE superhydrophobic surface were investigated. It was demonstrated that the maximum static contact angle was up to 168.36°. The degree of anisotropy could be controlled by adjusting the micro channels spacing. The as-prepared PTFE superhydrophobic surfaces exhibited self-cleaning properties, and water droplets were easy to take away dusts attached to the surfaces. Especially, it was found using the self-made icing monitoring system that as-prepared PTFE superhydrophobic surface showed an outstanding dynamic anti-icing performance even if the surface temperature was as low as −25 °C and surrounded by ice and frost. The present study therefore suggests that CO2 laser microprocessing could be applied to large-scale preparation of superhydrophobic surface for practical applications in different fields of self-cleaning, anti-icing, microfluidic devices, lab-on-chips system, directional water harvesting, drag reduction and other fields.

Scheme diagram of the self-made icing monitoring system.130