Modified ceramic membrane with pH/ethanol induced switchable superwettability for antifouling separation of oil-in-acidic water emulsions

Nowadays, oily wastewater is a harmful pollutant to the environment. Membranes with switchable wettability have great advantages in the oil-water separation. Herein, a novel ceramic composite membrane with switchable superwettability is fabricated by combining a dopamine-assisted nanoparticle coating process and a chemical grafting of copolymers with responsive groups. FESEM, XPS, FTIR, TG and contact angle measurements confirm the success of each surface modification steps. The as-prepared membranes transform from superhydrophobicity in air to superhydrophilicity in acidic aqueous solution (pH = 1) and recover to superhydrophobicity after immersion in ethanol. This superhydrophobicity-superhydrophilicity translation can repeat cyclically. The superwettability switchable membranes can effectively separate oil-water mixture and emulsions. Furthermore, good antifouling property of the composite membrane in filtration of oil-in-acidic water emulsions (pH = 1) has also been obtained. All these results show that this kind of ceramic composite membranes would have important applications in oil pollution control and industrial wastewater treatment.

Automated summary

This article presents a novel ceramic composite membrane with switchable superwettability for efficient oil-water separation and industrial wastewater treatment.