Unveiling the relationship between MOF porosity, particle size, and polyethersulfone membranes properties for efficient decontamination of dye and organic matter

Abstract

This work investigates the impact of reaction time on the textural properties and nanoparticles growth of metal organic framework (MOF) obtained from zinc substrate and their subsequent impact on the performance of polyether-sulfone (PES) ultrafiltration membranes. The MOF nanoparticles were synthesized at various reaction times between 2 and 8 h and then immersed in ascorbic acid to improve their hydrophilicity. A decline in the particle size with significant rise in the textural properties was noticed by decreasing the reaction time. Moreover, shifting of oxygen functional groups (–OH and C–O) was obtained after acid treatment. Next, 1.5 wt% of the acid treated MOFs were blended in the PES polymer for the formation of the hybrid membranes. The porosity, contact angle, water flux, surface morphology, and roughness were characterized for the resulting membranes. Moreover, the hybrid membranes were tested against the rejection of Eriochrome Black-T (EBT) and Humic acid (HA) pollutants. The characterization outcomes illustrated an incremental rise in hydrophilicity, porosity, and surface roughness of the hybrid membranes by decreasing the reaction time of the MOF nanoparticles. The water flux steadily improved by decreasing the reaction time of the MOFs. The maximum flux was 427.7 L m−2h−1 which was 2.2 times higher than the flux of the bare membrane. The elimination of EBT and HA, flux recover ratio and fouling resistance of both pollutants were improved by decreasing the particle size of MOFs. Overall, this study discloses that tuning the reaction time of MOF significantly influence the effectiveness of PES membranes in water treatment systems.