Publication

Abstract : The potential applications of superhydrophobic surfaces have garnered significant interest among researchers. While numerous methods have been proposed to achieve superhydrophobicity on various materials, only a limited number are suitable in terms of process simplicity, productivity, and cost-effectiveness. In this study, a hot embossing process was employed to enable Teflon surfaces as superhydrophobic surfaces with the bio-inspired surface micro / nano features, addressing these limitations. Bioinspired dual-scale roughness patterns were created on a copper surface through sandblasting, followed by electrochemical etching. Using the patterned copper master, the reverse of dual-scale roughness patterns was subsequently transferred onto a polytetrafluoroethylene (PTFE) surface via hot embossing. By systematic variation of electrochemical etching parameters such as current density and etching time, and hot embossing parameter i.e., hot press temperature, the appropriate dual scale, i.e., micro / nano structures have been enabled on the Teflon surface to imbibe with superhydrophobic characteristics. As a result, the fabricated superhydrophobic surfaces exhibited an average static water contact angle (SWCA) of 150°. These surfaces are checked its superhydrophobic robustness by investigating the retraction dynamics of the impacting water droplet with different impact velocities. By understanding the robustness in static water droplet contact angle and retraction dynamics of the impacting drop on these surfaces, these superhydrophobic characteristics can be extended in solving ice aggregation control on airborne structures and bio-fouling control in marine structures.