Poly(vinylidene fluoride) ultrafiltration membranes tailored with zirconium-based MOF-801 for water treatment applications

Abstract

Highly hydrophilic and antifouling poly(vinylidene fluoride) (PVDF) ultrafiltration membranes are developed with excellent permeation using a zirconium-based metal–organic framework (MOF-801). MOF-801 is synthesized by a solvothermal method using zirconium(IV) oxychloride octahydrate (ZrOCl₂⋅8H₂O) and fumaric acid. The chemical functionality of MOF-801 is studied by Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) whereas surface morphology and elemental composition are probed by scanning electron microscopy (SEM)/energy-dispersive X-ray analysis (EDX). The PVDF/MOF-801 membranes are characterized in terms of FTIR, XRD, FESEM/EDX and atomic force microscopy. The performance of the hybrid PVDF/MOF-801 membranes in terms of pure water flux and antifouling ability is found to be improved compared with bare PVDF membranes. The wettability of the membranes is measured by water contact angle and found to be 76.7° for bare PVDF membrane, which decreases upon the addition of MOF-801 to 55.1° due to the increase in surface hydrophilicity. A notable increase in roughness of 226.29 nm and a porosity of 67.91% is observed for the addition of 2 wt% MOF-801 in PVDF membrane matrix. The flux recovery ratio of the hybrid membrane is increased from 66.4% to 89.6% and from 68.3% to 85.2% for bovine serum albumin (BSA) and humic acid (HA) separation, respectively. In addition, the reversible and irreversible fouling performance during the rejection of BSA (93%) and HA (88%) indicates the enhanced antifouling property of the PVDF/MOF-801 membranes. A zone of inhibition test evidences the outstanding antibiofouling activity of the PVDF/MOF-801 membranes against E. coli and S. aureus. Overall results demonstrated the suitability of hybrid PVDF/MOF-801 membranes for water and wastewater treatment. © 2023 Society of Industrial Chemistry.