High-performance oil-water separation polytetrafluoroethylene membranes prepared by picosecond laser direct ablation and drilling

Abstract

The membranes with special surface wettability have attracted considerable attention, especially in the practical applications of oil-water separation. Here, we presented a simple and rapid method of picosecond (ps) laser direct ablation and then drilling to fabricate high-performance oil-water separation polytetrafluoroethylene (PTFE) membrane. It was found that the as-prepared rough PTFE membranes had ca. 0° contact angle (CA) of oil in air and above 150° CAs of water in air or oil, respectively, exhibiting superoleophilicity and under-oil superhydrophobicity. The micropore size of the membranes was less than ca. 180 μm, the corresponding separation efficiencies were over 99.0% for different oil-water mixtures due to the special and rough surface microstructures. Importantly, the separation efficiencies and fluxes of the as-prepared membranes showed no obvious change with suffering heavy erosion or 40 separation cycles, indicating that the membranes had excellent stability and applicability. Additionally, the effect of the special and rough surface on oil-water separation performance was investigated. This work provides a new pathway for the rapid fabrication of high-performance separation membranes. Keywords: Polytetrafluoroethylene, Superhydrophobicity, Superoleophilicity, Oil-water separation, Picosecond laser ablation