A durable bio-based polybenzoxazine/SiO2 modified fabric with superhydrophobicity and superoleophilicity for oil/water separation

It is imperative to develop efficient and durable separating materials to treat oily waste-water. In this work, Cardanol, which can be easily obtained from cashew nut shell, was employed to synthesize benzoxazine monomer (C-a), and superhydrophobic/superoleophilic PC-a/SiO2 films were further prepared on commercial polyester fabrics through a simple spray coating technique followed by a thermal curing method. The resultant PC-a/SiO2 fabrics had an excellent performance for several types of heavy oil/water separation driven solely by gravity, with oil fluxes of around 6500–9500 L·m−2·h−1, separation efficiencies of all over 90%, and an excellent recyclability. In addition, the PC-a/SiO2 fabrics achieved efficient collection of light oil from water. More importantly, PC-a/SiO2 fabrics possessed a self-cleaning property and a strong durability in harsh environments, such as acid/alkali immersion, UV irradiation and high temperature treatment. Hence, the bio-based PC-a/SiO2 modified fabric has a promising future in the field of oil/water separation.