A novel and facile antibacterial sponge for effective demulsification and oil/water emulsions separation

A novel underwater superoleophobic sponge for emulsion wastewater treatment was fabricated by [3-(methacryloylamino)propyl]trimethylammonium chloride polymer. The emulsion separation effi-ciency, antibacterial ability, and the mechanism of the automatic demulsification phenomenon of the prepared sponge were investigated. The experimental results showed that the sponge exhibited the property of underwater superoleophobicity and its separation efficiencies for separating oil/water emulsions of chloroform, heptane, kerosene, toluene, and vegetable oil were above 99%. Besides, the sponge’s antibacterial efficiency was above 99% for Escherichia coli and Staphylococcus aureus. In addition, the prepared sponge had high sodium dodecyl sulfate (SDS) adsorption ability; therefore, it could change the ionic balance of the emulsions stabilized by SDS. The destroyed emulsions would be aggregated to form large but unstable emulsions. Consequently, these unstable emulsions would be separated, leading to the formation of the oil layer. This schematic mechanism of the automatic demulsification phenomenon was also proposed in this study.