Porous superhydrophobic‐superoleophilic polytetrafluoroethylene fibrous membranes with tertiary structures for efficient oil/water separation

Abstract The separation of stable oil/water emulsions is an urgent global issue. In this work, a porous and superhydrophobic polytetrafluoroethylene (PTFE) fibrous membrane was obtained by first centrifugal spinning PTFE/potato starch fibers and then heat treating the fibers to remove the starch. Results showed that spherical protrusions and irregular striped protrusions appeared on the surface of the prepared PTFE fibers, which significantly increased the roughness and hydrophobicity of the fibrous membrane. In addition, number density and shapes of these protrusions could be tuned by changing the extent of the heat treatment and the potato amylose content during the fiber preparation. The water contact angle on the structured PTFE membranes was as high as 160°, and the water sliding angle was as low as 3.4°. The results of oil/water separation experiments showed that the oil removal rate reached 99.5% based a permeability of 3670 L/m 2 /h, which suggested that the obtained PTFE fibrous membrane has great potential for use in oil/water emulsions separation.