Construction of a Multiscaled Synergistic Membrane for Efficient Dye Adsorption and Emulsion Separation

Water filtering materials have become a research hotspot, as environmental contamination, particularly water pollution, poses a severe threat to human health worldwide. Hence, flower-like multiscaled difunctional synergistic membranes exhibiting superhydrophilicity and underwater superoleophobicity were fabricated via electrospinning and hydrothermal methods for oil/water separation and dye adsorption. Furthermore, the morphology, chemical composition, wettability, water transmission, and oil resistance of the prepared membranes were tested and analyzed. The comprehensive properties of the membranes were evaluated through oil/water separation and dye adsorption. The results show that the obtained flower-like multiscaled [polyamide 66 (PA66)@MIL] membrane has excellent wettability and outstanding oil resistance properties in water (an underwater oil contact angle of 161.08°). Also, after several filtration cycles, the membrane still maintains a high recovery flux (nearly 99%). In addition, the removal rate of the methylene blue solution of the PA66@MIL membrane reached 91.24% after 5 cycles of the adsorption and filtration process due to the synergia of the nanofiber membrane and flower-like material. Moreover, the obtained membrane displayed remarkable stability and retained outstanding hydrophilicity under various harsh conditions (acid, alkali, salt solution, and sonication). This method can provide valuable guidance for the design of high-performance oil/water separation membranes suitable for multiple application scenarios.