A universally applicable method for fabricating superhydrophobic polymer surfaces

The modification of polymer surfaces to manipulate their wetting properties is of great technological importance. It is well known that surface chemistry and topography jointly determine the nature of wetting on a surface. In this study, we show a cheap and effective process universally applicable to fabricate superhydrophobic surfaces on various polymers. The process combines sanding and reactive ion etching treatment of the polymer surface to generate respective micro and nanoscale surface roughness, which is followed by subsequent coating of a fluorinated silane molecule to modify the surface chemistry. A 5 min reactive ion etching treatment after sanding is sufficient to achieve nanoscale roughness required for superhydrophobic surfaces. The polymer surfaces so produced retain their superhydrophobicity for more than 90 days, demonstrating the stability of the micro and nanoscale surface roughness and the hydrophobic surface coating. Similar results are obtained with different polymers such as poly(methyl methacrylate) (PMMA), polycarbonate (PC) and cyclo-olefin copolymer (COC), indicating that the process can be applied for creating superhydrophobic surfaces on general polymer substrates.