Synthesis of novel high-performance cotton-based superhydrophobic membranes for separation of oil/water mixtures and emulsions

Typical challenges in preparing superhydrophobic membranes through the coating method for oil/water separation are the long manufacturing processes, the emission of volatile organic compounds, and the reduction in separation efficiency with an increasing number of cycles. In this work, we report a short process and environmentally friendly coating method for preparing superhydrophobic membranes on cotton fabric. The membrane was mechanically robust, which could withstand at least 2000 cycles of Martindale abrasion and maintain its superhydrophobicity. The membranes demonstrated high separation efficiency (> 97.8%) and high permeate flux (> 21.9 kL m −2  h −1 ) for oil/water mixtures and emulsions. After the separation and membrane cleaning processes, the structural rearrangement of covalent adaptable networks (CANs) of disulfide bonds at 90 °C induced the self-healing on the WCA, ensuring efficient and long-term oil/water separation even in acidic (pH 1) or alkaline (pH 14) environments for 20 days. The development of cost-effective, environmentally friendly, scalable, mechanically robust, chemically stable, and self-healing superhydrophobic membranes will provide new possibilities for efficient and long-term separation of complex oily wastewater. Graphical abstract