Simultaneous, efficient and continuous oil–water separation via antagonistically functionalized membranes prepared by atmospheric-pressure cold plasma

For decades, oil and water separation has remained a challenge. Not only oil spills but also industrial oily wastewaters are threatening our environment. Over the years, oil–water separation methods have been developed, however, there are still considerable hurdles to overcome to provide a low cost and efficient process able to treat a large amount of liquid. In this work, we suggest a continuous, simultaneous and effective oil–water separation method based on the antagonistic functionalization of meshes using atmospheric pressure cold plasmas. Using this robust plasma method, superhydrophobic/underwater-superoleophilic or superhydrophilic/underwater-superoleophobic functionalized meshes are obtained. Antagonistically functionalized meshes can simultaneously separate oil and water and show continuous separation flow rates of water (900 L m⁻² h⁻¹) and oil (400 L m⁻² h⁻¹) with high purities (> 99.9% v/v). This fast, low-cost and continuous plasma-based process can be readily and widely adopted for the selective functionalization of membranes at large scale for oil-spill cleanup and water purification.