Investigation of electric field-aligned edge-oxidized graphene oxide nanoplatelets in polyethersulfone matrix in terms of pure water permeation and dye rejection

Herein, we have evaluated the impact of orientated edge-oxidized graphene oxide nanoplatelets (EOGO) in polyether sulfone (PES) membrane on the pure water permeability (PWP) and organic dye molecule rejection values. Aligned PES/EOGO nanocomposite films were prepared through electric field induction. Morphological, structural, and chemical-physical characterizations including atomic force microscopy, thermogravimetric analysis (TGA), contact angle, zeta potential, porosity, and PWP measurements were carried out. The results revealed successful aligned/oriented PES/EOGO nanocomposite formation at low-to-moderate EOGO loadings. Membrane function tests demonstrated an increase in water permeability at higher EOGO contents, up to 0.5 wt%, followed by a decrease at 1 wt% nanoplatelets due to nanoparticles agglomeration. The horizontal electric field (1000 Hz) processed samples indicated lower PWP in comparison with their vertical-field (34% decrement) and No-field (29% increment) counterparts as well as a better dye molecule rejection at 0.1 wt%, referring to nanoplatelets successful alignment at this loading level.