Superhydrophobic/Superoleophilic Surfaces by Electroless Nanoparticle Deposition and Perfluorinated Polymer Modification

Recent research on superhydrophobic/superoleophilic materials is focused on simplified methods of fabrication. In this study, a superhydrophobic surface was prepared by coating a Cu metal sheet with silver nanoparticles by immersion in an aqueous AgNO₃ solution followed by dip-coating with Nafion. The simple fabrication process is completed in less than 40 min. This is significantly faster than most other reported techniques for preparing superhydrophobic/superoleophilic surfaces. The as-prepared coated sample possessed low surface energy and exhibited surface roughness with nano- and micro-hierarchical features. Due to its extreme anti-wetting property, the coating showed protective properties against corrosive media, as evidenced by electrochemical impedance spectroscopy and potentiodynamic polarization measurements. Aside from being able to repel water, the coating, when applied to a Cu metal mesh, also displayed superoleophilicity such that it permitted the passage of oil through the mesh openings. Thus, the coated mesh acts as a separation membrane, which is useful in oil/water separation application.