Remarkable permeability enhancement of polyethersulfone (PES) ultrafiltration membrane by blending cobalt oxide/graphene oxide nanocomposites

Abstract

Novel polyethersulfone (PES) ultrafiltration membranes blended with cobalt oxide/graphene oxide (Co₃O₄–GO) nanocomposites were prepared by the phase inversion method. The hybrid membranes were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and energy dispersive spectrometry (EDS). Moreover, the permeability, antifouling, and mechanical and antibacterial properties of the membranes were studied. The experimental results indicated that the pure water flux of the hybrid membrane was improved from 101.1 L m⁻² h⁻¹ to 347.9 L m⁻² h⁻¹ compared to that of the pristine membrane. In addition, the antifouling performance was investigated by a series of aerobic activated sludge (SV = 30%) filtration experiments and the permeability recovery ratio of nanosheet-embedded membrane (81.1%) was significantly increased compared to that of the pristine membrane (55.7%). These significant improvements were mainly ascribed to the enhancement of surface hydrophilicity due to the decrease in the water contact angle from 75.20° to 54.75° and homogenous dispersion of the nanosheets in the polymer matrix. Furthermore, the remarkable improvement in the antibacterial performance (89.8%, against Escherichia coli) was also observed. In the study, we blended non-agglomerate metal oxide nanoparticles in polymer matrix to produce a variety of functional materials/membranes for water purification.