A novel polyesteramide thin film composite nanofiltration membrane prepared by interfacial polymerization of serinol and trimesoyl chloride (TMC) catalyzed by 4-dimethylaminopyridine (DMAP)

In order to integrate the advantages of polyamide thin film composite (TFC) nanofiltration (NF) membranes and that of polyester TFC NF membranes, a novel polyesteramide (PEA) TFC NF membrane was prepared by interfacial polymerization between serinol and trimesoyl chloride (TMC) and catalyzed by 4-dimethylaminopyridine (DMAP) on a flat-sheet polyethersulfone (PES) substrate membrane. The membrane performance was maximized by optimizing different preparation parameters. The reaction process was divided into four basic patterns. X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy confirmed the membrane had a partially cross-linked active layer that contained ester bonds, amide bonds and residual hydroxyl groups. Morphology analysis showed the surface of the PEA-TFC-NF membrane was grainy, which was different from the typical polyamide membranes. The contact angle and zeta potential measurements confirmed the PEA-TFC-NF membrane was highly hydrophilic and negatively charged across the entire pH range tested. The optimized PEA-TFC-NF membrane had a MWCO of 474 Da and water permeability of 6.0 L m(-2) h(-1) bar(-1) at 0.5 MPa and 25 degrees C. The membrane salt rejections followed the order of Na2SO4 > MgSO4 > NaCl > MgCl2, which were 96.27%, 83.92%, 58.68% and 28.76%, respectively. Moreover, the PEA-TFC-NF membrane displayed good antifouling ability.