Structural manipulation of PES constituents to prepare advanced alternative polymer for ultrafiltration membrane

Polyethersulfone (PES) is the most well-known polymer for the preparation of ultrafiltration (UF) membrane, but its membrane suffers from fouling. In this study, two engineered polymers were synthesized to provide optimal antifouling properties for UF membranes that simultaneously benefit from good properties of polyamide and PES. The choice of polyamide is due to its prominent characteristics and the convenience of its synthesis with various functional groups in a cost-effective way. Two hydroxyl containing polyamide bearing sulfone groups (PAS) and ether group (PAE) were synthesized by polycondensation method. The UF membranes were fabricated using the phase inversion method via immersion precipitation of PAS, PAE, and PES in dimethylacetamide, as a solvent and water, as a nonsolvent. The obtained membranes were compared and characterized by means of atomic force microscopy, scanning electron microscopy, contact angle, and Fourier transform infrared spectroscopy in the attenuated total reflection mode. The performance of membranes illustrated that the PAS and PAE membranes in comparison with the PES membrane had better porosity, water permeability, lesser protein fouling, more vertically finger-like pores, and more hydrophilic surface. The water permeability of PES, PAE, and PAS was 7.3, 64.0, and 78.0 L m⁻² h⁻¹ while their flux recovery ratio was 59.4, 83.3, and 86.7%, respectively. The promising permeability and antifouling properties of the PAS are potentially applicable in the efficient industrial separation and wastewater treatment.