Abstract
Incorporating graphene oxide (GO) into polymeric materials has several potential advantages, including increasing the antifouling properties, selectivity, permeability, and mechanical strength. However, in GO, the graphene layers have strong, cohesive forces, making it difficult to get exfoliated graphene sheets. As a result, the GO sheets tend to agglomerate, and that hinders some of its applications.
To reduce the aggregation and improve the dispersion and interaction of the GO material with the polymer matrix, GO was functionalized with 3-aminopropyl triethoxysilane (APTES). GO-APTES was then combined with highly porous zeolitic Imidazolate Framework (ZIF-8) to form ZIF-8@GO-APTES hybrid at different ZIF-8 loading (0.1 - 1.5 wt.%). The ZIF-8@GO-APTES were used as a filler at concentrations of 0.5 and 1.0 wt.% to fabricate polyacrylonitrile (PAN) ultrafiltration (UF) membranes via the phase inversion method. The effect of ZIF-8@GO-APTES filler on the hydrophilicity, surface morphology, water flux, rejection performance, and fouling resistance was investigated. The incorporated fillers increased the membrane porosity, hydrophilicity (water contact angle (WCA) decreased from 69.5o to 25.9o), and permeation flux (increased from 31.3 Lm-2h-1 to 101.3 Lm-2h-1) of the PAN membrane. Moreover, the composites membranes rejected >70% of MO- and >40% of MB+ through electrostatic exclusion mechanism compared to PAN membranes with rejection percentages of 61% of methyl orange (MO) and 33% of methylene blue (MB). The quality of the textile wastewater was also improved after rejection with ZIF-8@GO-APTES/PAN composites membranes. The composites membranes showed an increase in the removal efficiency of dyes with respect to an increase in ZIF-8 loading in the composites and an increase in ZIF-8@GO-APTES loading in the PAN membranes...