Janus superwetting fabric for effective emulsion separation

Abstract Superwetting membranes have superior advantages in the treatment of oil contaminated wastewater, especially when it is in an emulsified state. However, these types of membranes suffer from size-sieving limitations. Here, a Janus membrane was constructed by integration of superhydrophobic/underwater superoleophilic and superhydrophilic/underwater superoleophobic fabrics. Under gravity induced flow, water rapidly passes from the superhydrophobic to the superhydrophilic sides of this membrane while oil droplets are retained by the superwetting interface via an “attraction-aggregation-coalescence” process, realizing highly efficient emulsion separation.