Porous materials with opposing superwettability toward oil and water have aroused widespread interest for their selective-wetting advantage in oil-water separation. The separation process, however, requires constant energy input to maintain the driving force. Further reducing the external energy consumption or accelerating the liquid transport during separation is still a challenge. The Janus membrane is an emerging porous material with opposing wettability toward a specific liquid on each side. The asymmetric wettability distribution leads to a surface energy gradient-driven liquid-transport behavior through the thickness, which significantly facilitates liquid transportation. It is conceived that porous materials possessing both Janus features and selective superwettability would reduce energy consumption and strengthen the efficiency in oil-water separation. Herein, a novel durable superoleophobic (SOHB) Janus fabric which possesses oil-repellent and surface energy gradient-driven water-transport properties was developed through one-side superoleophobic/superhydrophilic modification of the superamphiphobic fabric. The SOHB Janus fabric exhibits high mechanical durability and significant superior capacity than the homogeneous superoleophobic/superhydrophilic fabric in separating various oil-water mixtures. Moreover, the SOHB Janus fabric repels oil contaminants and pumps perspiration from the human skin, exhibiting prospects in physical moisture regulation and comfort improvement. Our novel Janus fabric, along with the fabrication principle, provides a feasible solution for energetic-efficient oil-water remediations and would have implications for the fabrication of advanced separation membranes and intelligent functional clothing.
Keywords: Janus; energetic-efficient; oil−water separation; selective wettability; superoleophobic/superhydrophilic.