Robust superhydrophobic polyurethane sponge functionalized with perfluorinated graphene oxide for efficient immiscible oil/water mixture, stable emulsion separation and crude oil dehydration

In recent years, graphene oxide (GO), prepared by the modified Hummers' method, and its derivatives have become a focus of research owing to their outstanding physical and chemical properties and low cost. Drawing inspiration from the mussel protein, a facile and environmentally-friendly method was employed to fabricate superhydrophobic/superoleophilic reduced graphene oxide (rGO) derivative. The preparation comprises two steps: coating GO nanosheets with polydopamine (PDA) and subsequent reaction with 1H,1H,2H,2H-perfluorodecanethiol. Due to the excellent adhesive ability of PDA, the resulting fPDA modified rGO nanosheets (rGO-fPDA) were firmly immobilized onto polyurethane (PU) sponge skeleton by a simple drop-coating method. The as-prepared rGO-fPDA functionalized sponge exhibited superhydrophobic behavior with a water contact angle of 162 degrees +/- 2 degrees, high organic adsorption capacity, recyclability and stable oil/water separation behavior under different acidic/alkaline conditions. Due to its facile fabrication technique and outstanding properties, the superhydrophobic-superoleophilic PU-rGO-fPDA sponge holds great promise as an oil adsorbent for cleaning up large-scale pollution of oil and organic solvents, and dehydrating crude oil.