Synergistic effects of combining ZIF-8 and graphene oxide inside cellulose acetate-based mixed matrix membranes on the removal of methylene blue

Mixed matrix membranes (MMMs) combining zeolitic imidazolate framework-8 (ZIF-8) and graphene oxide (GO) within a cellulose acetate (CA) matrix were fabricated via phase inversion for methylene blue (MB) dye removal. ZIF-8 introduced rigid microporous domains that enhanced dye retention through adsorption and steric hindrance, while GO improved membrane hydrophilicity and filler dispersion. SEM and XRD analyses confirmed uniform filler incorporation and partial structural ordering, whereas excessive GO loading reduced apparent crystallinity. ZIF-8 incorporation increased membrane hydrophobicity and reduced permeability; however, the addition of GO partially mitigated this effect, leading to improved flux relative to ZIF-8-only membranes while maintaining high rejection. The optimized CA/ZIF-8 + GO membrane achieved 99.7% MB removal, demonstrating a synergistic balance between permeability and selectivity. These findings highlight the potential of hybrid-filler CA-based MMMs as sustainable adsorptive ultrafiltration membranes for dye wastewater treatment, supporting SDG 6 and SDG 12. • Cellulose acetate (CA)-based mixed matrix membranes were developed for dye removal • ZIF-8 improved dye rejection via dense pores, electrostatic, and functional interactions • Graphene oxide (GO) enhanced hydrophilicity and enabled flux recovery of the MMMs • CA/ZIF-8 + GO MMMs achieved up to 99.7% methylene blue removal