Fabrication of PSf nanocomposite membranes incorporated with ZnFe layered double hydroxide for separation and antifouling aspects

Herein, we report the effect of blending of various concentrations of ZnFe layered double hydroxide (LDH) on the filtration, antifouling, and antibacterial performances of Polysulfone (PSf) nanocomposite membranes for BSA and dye separation. ZnFe LDH with a molar ratio of M²⁺:M³⁺=3:1 was synthesized by the co-precipitation method. The PSf-ZnFe LDH nanocomposite membranes exhibited higher hydrophilicity (the lowest contact angle value of 64.42°), porosity (up to 58.7), and mean pore radius compared to the pristine PSf membrane. The water flux of the PSf-ZnFe LDH nanocomposite membrane (LDH content of 2.0 wt% of PSf) was 105 L/m²h, which is 2.3 times higher than the flux of pristine PSf membrane of 45 L/m²h. The rejection ratios for the fabricated membranes were 93%, 83%, and 16% for BSA, reactive red 198, and methylene blue, respectively. Additionally, 2.0 wt% ZnFe LDH incorporated membrane demonstrated better antifouling performance with a flux recovery ratio (FRR) of 95% compared to the pristine PSf membrane with 42% of FRR. Consequently, a bacterial viability inhibition test was utilized to determine the antibacterial properties, and the ZnFe LDH exhibited a high inhibition capacity. The fabricated PSf-ZnFe LDH nanocomposite membranes exhibited a higher filtration, antifouling, and antimicrobial performance as compared to pristine PSf.