ECTFE hybrid porous membrane with hierarchical micro/nano-structural surface for efficient oil/water separation

Superhydrophobic-superoleophilic poly(ethylene chlorotrifluoroethylene) (ECTFE)-SiO2 hybrid porous membrane with hierarchical micro/nano-structural surface was successfully fabricated via thermally induced phase separation (TIPS) method using bis(2-ethylhexyl) adipate (DEHA) and diethyl phthalate (DEP) as binary diluent, hydrophobic SiO2 as the additive. The effect of SiO2 content on the morphology, pore size distribution, wettability and mechanical properties of prepared membrane was characterized by scanning electron microscope, automatic mercury porosimeter, contact angle goniometer and tensile testing instrument, respectively. The results showed that, the prepared hybrid membrane surface evolved into superoleophilic and superhydrophobic when the SiO2 content was 4 wt%. The separation experiments for different kinds of surfactant-free and surfactant-stabilized water-in-oil emulsions indicated that prepared superhydrophobic-superoleophilic membrane had high oil/water separation efficiency. The antifouling performance of the membrane was also studied for reuse many times in various pH conditions. This study provided a novel material and a facile method to fabricate superhydrophobic-superoleophilic membrane.