Underwater superoleophobic graphene oxide-connected cotton fibers membrane for antifouling oil/water separation

Underwater superoleophobic membranes constructed by coating superhydrophilic materials on various porous substrates have been widely used for oil/water separation. However, most of these membranes suffer from highcost, non-green and complex fabrication process. Herein, a novel graphene oxide-connected cotton fibers (GOCCF) membrane was fabricated by simply soaking cotton in graphene oxide (GO) aqueous-alcoholic suspension followed by air-drying. The synergistic effect of the rough surface and the hydrophilic polar groups on the GO nanosheets endows the GOCCF membrane with superhydrophilicity and underwater superoleophobicity. The GOCCF membrane can be applied to oil/water separation, and exhibits high separation efficiency for separating water from various oils driven by gravity. The GOCCF membrane also shows remarkable antifouling behavior and recyclability with maintaining a high separation efficiency over 99.8% and an ultra-high flux about 95,000 L m- 2 h-1 in the whole separation processes repeated for 30 cycles. These results suggest that the GOCCF membrane could be a potential material for practical oil/water separation.