Polyethersulfone-TPU blend membrane coated with an environmentally friendly sabja seed mucilage-Cu2 + cross-linked layer with outstanding separation performance and superior antifouling

Abstract

In this study, membranes were prepared by blending polyethersulfone (PES) with thermoplastic polyurethane (TPU) in order to enhance the mechanical properties of PES membranes. The membranes were fabricated using the vapor-induced phase separation coupled with non-solvent induced phase separation (VIPS-NIPS method) for the purpose of preventing the formation of macro-voids and enhancing the mechanical stability. After the formation of the PES-TPU membranes, a layer of Sabja seed mucilage (SSM), as an eco-friendly low-cost polysaccharide, was fabricated on the membranes surface, and then chelated via Cu2+ ions, in order to enhance the rejection performance of the prepared membranes. The PES-TPU coated with Sabja seed mucilage-Cu2+ (PES-TPU@SSM/Cu) exhibited not only high permeance of 7.97 L/m2.h.bar, but also extraordinary dye and pharmaceutical residue rejection performance of 98.4% methylene blue, 99.5% crystal violet, 98.2% ceftriaxone and 97.6% amoxicillin, arising from the formation of the cross-linked dense SSM/Cu layer. Moreover, all the antifouling parameters of the fabricated membrane were boosted by SSM/Cu coating on the membrane surface and the long-term durability of the membrane was also investigated after 10 days, exhibiting no significant changes in the membrane performance. Furthermore, mechanical properties were remarkably meliorated by TPU addition.