Development and investigation of high-flux antifouling NF PES membranes decorated by aniline oligomers and application for wastewater treatment

In this research, first branched aniline oligomers functionalized polyethersulfone (BAO-PES) were prepared by diazonium-induced grafting, and then the embedded membranes were fabricated at five different compositions using the conventional phase inversion process. The influence of BAO-PES as a modifier on membrane preparation was investigated in terms of membrane topography, membrane morphology, hydrophilicity, permeability, antifouling performance, and chemical stability. The function of blended membranes was evaluated by computational analysis, Fourier transform infrared (FTIR) analysis, scanning electron microscopy (SEM), atomic force microscopy (AFM), and water contact angle (WCA) measurement. Our computational analysis has substantiated that BAO-PES (25 wt. %)/PES, characterized by a lower Flory-Huggins parameter (0.65), emerges as a promising contender for the blending of BAO-PES with PES. The maximum water flux of 67.6 kg/m(2) h was observed for the M-1 membrane with the optimum dosage of BAO-PES (25 wt. %) at a low pressure of 3 bar. To assess the nanofiltration performance of the mixed matrix BAO-PES/PES membranes, the removal efficiency was studied for Direct Red 16 and tannic acid dye. From the results, it was found that the loose BAO-PES/PES membranes had great dye rejection ability (more than 97%) compared to the bare membrane (88%-89%). The fouling resistance property of the loosely prepared membranes was tested by protein rejection, and the results revealed that the best antifouling property was observed at optimum dosage of the BAO-PES modifier (25%, FRR = 98.37%). The embedded BAO-PES/PES membranes, after exposure to harsh environments, exhibited such long-term chemical stability that it is an important specification for real management in industry.