Polysulfone/Polyetherimide Ultrafiltration composite membranes constructed on a three-component Nylon-fiberglass-Nylon support for azo dyes removal: Experimental and molecular dynamics simulations

Dyeing wastewater from textile industries is often contaminated with chemical pollutants, which causes severe water pollution problems that are challenging to treat. Herein, we report the development of laminated membranes consisted of polysulfone (PSf)/polyetherimide (PEI) layers coated on Nylon-fiberglass-Nylon support by spin/spray-coating technique for the removal of reactive black 5 (RB5) and basic red 18 (BR18) from aqueous solutions via membrane Ultrafiltration (UF). In addition to a pristine polysulfone (PSf) membrane, composite membranes were prepared with 25 wt% (CM25), 30 wt% (CM30), and 35 wt% (CM35) of PEI, and characterized in terms of morphological, wetting, mechanical, and water transport properties along with surface charge and mean pore diameter. Morphological characterization by SEM showed homogeneous and uniform distribution of PSf/PEI membrane layer on the Nylon-fiberglass-Nylon support. Moreover, mechanical tests showed that the stress and strain at the breaking point of membranes were remarkably changed after coating it with Nylonfiberglass-Nylon support. The addition of PEI had a significant influence on the hydrophilic character of prepared membranes. Filtration results indicated that the incorporation of PEI in composite membranes improved the pure water permeability (PWF) up to 79.11 L m-2 h-1 bar-1 compared to that of PSf alone (29.36 L m-2 h-1 bar1). The combined effect of Nylon-fiberglass-Nylon support and the PSf/PEI membrane layer has certainly enhanced the filtration performance, making prepared UF membranes potential candidates for scale-up industrial applications.