Dynamic (de)wetting properties of superhydrophobic plasma-treated polyethylene surfaces

Superhydrophobic surfaces present properties of self-cleaning and unwetting that could be applied in the optics field. The wetting and dewetting of these superhydrophobic surfaces are compared to that of only hydrophobic polyethylene. The contact angle of such a surface varies from 170 degrees to 130-140 degrees. The dewetting is studied using two techniques of dynamic dewetting measurements. The behaviors of surfaces, dried or prewetted with water vapor, are different. The dewetting of the dried surface previously prewetted is discontinuous, and slower than that of the dry one. This specific behavior is interpreted as a roughness effect on trapped water. However, its dewetting is still faster than a corresponding hydrophobic surface like polytetrafluoroethylene (PTFE). Copyright (c) 2006 John Wiley & Sons, Ltd.