Superhydrophilic and superoleophobic chitosan-based nanocomposite coatings for oil/water separation

To overcome easy oil fouling and poor efficiency of traditional oil/water separation materials, superhydrophilic and superoleophobic coatings were fabricated by spray casting chitosan (CTS)-based nanocomposites. The molecular rearrangement of hydrophilic and oleophobic constituents, combined with the hierarchical rough surface structures, enabled a coating with a water contact angle of 0A degrees and a hexadecane contact angle of 157A degrees A A +/- A 1A degrees. Hexadecane droplets can easily slide off the dried and water-wetted coating without leaving any obvious oily trailing stains. When the superhydrophilic and superoleophobic CTS-based nanocomposite coatings were applied to oil/water separation, they exhibited excellent anti-fouling capacity, high separation efficiency and easy recyclability. The superhydrophilic and superoleophobic CTS-based coating would be a good candidate for the treatment of industrial oil-polluted water and the cleanup of oil spills.