Designing of nanotextured inorganic-organic hybrid PVDF membrane for efficient separation of the oil-in-water emulsions

Abstract

The separation of the emulsified oil/water is one of the critical environmental challenges. The PVDF membranes have been found helpful for separation, but rapid fouling makes them less attractive in treating oil-in-water emulsions. The design of antifouling membranes has become an area of deep interest. Herein, developing a novel modified PVDF ultrafiltration membrane was reported by doping the pyrrole and solidifying it in a ferric-containing coagulation bath, resulting in a unique nanotextured PVDF membrane (CCB-Fe/PP_np-PVDF) to separate the oil/water emulsions. The resultant CCB-Fe/PP_np-PVDF membrane was thoroughly characterized using the FTIR, FE-SEM, EDX, mapping, AFM, and contact analyzer. The hydrophilicity of the CCB-Fe/PP_np-PVDF was substantially improved, and the water contact angle was reduced from 81֯ ± 0.9֯ to 44֯ ± 1.7֯. The CCB-Fe/PPnp-PVDF membrane flux increased by 121% compared to the pristine PVDF membrane, with high separation efficiency of 99%. The hydrophilic nanotextured surface of the CCB-Fe/PP_np-PVDF membrane showed good antifouling behavior, with a flux recovery ratio (FRR) of more than 96%. Irreversible flux was just less than 4%. The high flux recovery ratio indicated that the nanotextured surface produced by the Fe/PP_np had prevented the blockage of the membrane pores and compact cake layer formation, which makes it an excellent membrane for oil/water emulsion separation. This strategy can be adopted for designing advanced membranes for separation applications.