Poly(vinylidene fluoride)/partially alkylated poly(vinyl imidazole) interpolymer ultrafiltration membranes with intrinsic anti-biofouling and antifouling property for the removal of bacteria

Abstract

Bacterial contaminated water causes potential health issues. Conventional chlorine treatment has shortcomings of environmental hazards and chlorine adoptability by the bacterial cells. Ultrafiltration membrane can intercept bacterial species from feed water. Membrane having anti-biofouling/antifouling properties is needed for the removal of bacteria from feed water. Herein, interpolymer membranes with inherent antimicrobial activity and fouling release property have been prepared by the blend of poly(vinylidene fluoride) (PVDF), poly(vinyl pyrrolidone) and partially long chain alkylated (C12 chain) poly(vinyl imidazole) copolymer (PVIm-co-PVIm-C12) followed by cross-linking of the remaining VIm groups with an activated di-halide compound. The membranes obtain with copolymers of degree of alkyl substitution (DSC12) in the range of 0.75–0.85 and amount in the range of 0.9–3.5% w/w in the casting solutions exhibit good antimicrobial activity (>99 % of inhibition) and dynamic anti-biofouling property. The membrane prepared with 0.9% w/w of the copolymer (DSC12=0.85) shows higher flux recovery ratio (91 % for bacterial filtration and 88 % for protein filtration) compare to a pristine membrane (57 % for bacterial filtration and 58 % for protein filtration). The membrane is able to reject the bacteria completely. Use of small amount of copolymer and facile fabrication of stable anti-biofouling/antifouling membranes show potential for the purification of bacterial contaminated water.