A Superhydrophobic Trifluoromethyl-Containing Covalent Organic Framework Membrane for Efficient Oil/Water Separation

Oily water caused in the process of industry leads to not only the waste of resources, but also environmental pollution. Membrane separation, as a facile and efficient separation technology, has attracted widespread attention in the field of oil/water separation. The development of membrane materials with high separation performance is one of the key elements to improve separation efficiency. In this work, a superhydrophobic membrane composited with a trifluoromethyl-containing covalent organic framework (COF) is prepared, which exhibits excellent performance on separations of oil/water mixtures and water-in-oil emulsions. For different composition of oil/water mixtures, the highest flux of oil is up to 32 000 L m^-2  h^-1 and oil/water separation efficiency is above 99%. Moreover, the high oil/water separation efficiency remains unchanged after successive cycles. This work provides a feasible scheme for the design of high-efficiency oil/water separation membranes.