Fabrication and Characterization of Poly (Vinylidene Fluoride) Hybrid Ultrafiltration Membranes with Silver Loaded Mof-5 for Enhanced Permeation, Antifouling and Antibiofouling Performance

The zinc-based metal-organic frameworks (MOFs)such as MOF-5 and silver-loaded MOF-5 (Ag@MOF-5) are synthesized by facile solvothermal method and utilized to fabricate poly (vinylidenefluoride)(PVDF) hybrid ultrafiltration (UF) membranes for water treatment applications. As-synthesized MOF-5 and Ag@MOF-5 are characterized by ATR-FTIR, XRD, and SEM. The ATR-FTIR is used to validate the successful production of MOFs while the XRD pattern and SEM revealed their high crystallinity and cubical structure, respectively. The Ag@MOF-5 is verified by FTIR and SEM for its chemical functionality and morphology. From the SEM images, it is clearly seen the flaky structure of MOFs. The membranes are examined by ATR-FTIR, XRD, and SEM/EDAX. From the cross-section SEM images, macrovoids formed are visibly seen and the increase in roughness is obviously seen in AFM. The dispersion of MOF-5 and Ag@MOF-5 in the PVDF membrane matrix is validated via elemental mapping by the EDAX spectrum. The PVDF/Ag@MOF-5 hybrid membranes outperformed bare PVDF and PVDF/MOF-5 membranes in permeation and fouling properties, especially, the PVDF/Ag@MOF-0.5 (0.5wt% of Ag@MOF-5) hybrid membrane exhibited higher pure water flux (PWF) of 236.5 Lm-2h-1 and superior hydrophilicity with contact angle of 52.3°. Besides, PVDF/Ag@MOF-0.5 membranes demonstrated the enhancement in rejection of 98.4 and 96.5% and better antifouling with flux recovery ratio (FRR) of 89.7 and 92.4% for BSA and HA respectively. Moreover, PVDF/Ag@MOF-0.5 hybrid membranes displayed excellent antibacterial properties in the zone of inhibition test against E. coli and S. aureus. The overall findings indicate that the PVDF/Ag@MOF-0.5 hybrid membrane shows potential for the treatment of water and wastewater.