Fabrication of underwater superoleophobic metallic fiber felts for oil-water separation

Hierarchical nanoneedles-like Cu(OH)(2) structure coated stainless steel fiber felts (SSFF) with underwater superoleophobic (154 degrees +/- 2.2 degrees, n-octane, oil contact angle) and low-adhesive properties have been successfully fabricated via simple nanoparticles deposition and electrochemical oxidation methods. Meanwhile, when a water droplet (5 mu L) contacted the SSFF/Au/Cu/Cu(OH)(2) surface, it spread out quickly and reached a 0 degrees CA with very short time, suggesting a superior superhydrophilic property. The SSFF/Au/Cu/Cu(OH)(2) was used to separate oil-water mixtures, oil-corrosive salt solution mixtures and oil-in-water emulsions with high efficiency, which allowed water to permeate through while retained oil. In addition, the SSFF/Au/Cu/Cu(OH)(2) still maintained high separation efficiency above 99% after 5 emulsion recycling separation times. (C) 2018 Published by Elsevier B.V.