Gravity-driven and high flux super-hydrophobic/super-oleophilic poly(arylene ether nitrile) nanofibrous composite membranes for efficient water-in-oil emulsions separation in harsh environments

Abstract

Nanofibrous membranes with super-wetting feature exhibit promising application for oil/water emulsion separation, but achieving durability and high separation efficiency in harsh environments remains challenging. Herein, we developed a facile and effective strategy to prepare super-hydrophobic/super-oleophilic nanofibrous composite membranes, which perfectly integrated the two processes of electrospinning and fixing hydrophobic TiO2 nanoparticles to the surface of interconnected poly(arylene ether nitrile) (PEN) nanofibers using EVO-STIK serious glue. As a result, the constructed super-hydrophobic PEN/P–TiO2 nanofibrous composite membranes (WCA = 165 ± 2.4°) exhibited excellent separation efficiency (99.75 ± 0.12%) under gravity drive, with extremely high separation flux of 6853.65 ± 274 L/m2·h for surfactant-free emulsions and 3531.62 ± 231 L/m2·h for surfactant-stabilized emulsions. More importantly, the obtained PEN/P–TiO2 nanofibrous composite membranes showed stable super-hydrophobic feature and oil/water emulsion separation performance in harsh environments such as strongly corrosive solutions, physical damage, and high/low-temperature systems. Therefore, the super-wetting nanofibrous membranes with easy-handling, durable, and efficient oil/water separation performance could find potential application for emulsified oil-water separation system in harsh environments.