Retarded Interfacial Formation of Polyamine-Based Nanofiltration Membranes with Pyromellitic Acid: Separation, Acid Stability, and Antifouling Performance

Abstract

Crosslinked and additive-added polyamide thin-film composite (TFC) nanofiltration (NF) membranes formed by the conventional interfacial polymerization (IP) process have shown good performances. However, studies on polyamine TFC NF membrane prepared via an adjusted IP process with low-cost acid ligands as an interfacial additive for improved liquid-based separation are still lagging. In this regard, a polyamine-based TFC NF membrane synthesized by retarding the interfacial polymerization (IP) process with pyromellitic acid (PMA) (a polycarboxylate acid ligand) is herein reported. The PMA-adjusted membrane displayed a superb range of pure water fluxes from 9.8 to 20.4 L m–2 h–1 bar–1, with the best-performed membrane achieving up to 95.1% for Na2SO4 rejection. Thus, the water permeability of the PMA-TFC membrane is ∼2.4 times as high as the control TFC membrane. The best-performed PMA-TFC membrane showed good hydrophilicity, pressure resistance, and long-term filtration stability. In addition, the membrane structural stability was maintained with ∼3.9% declination in salt rejection after 30 days of immersion in 0.1 M HNO3 solution. Also, an impressive fouling resistance was achieved after three-cycle of bovine serum albumin fouling tests. This work, therefore, offers a more feasible way of designing polyamine-based NF membranes with good prospects in water reuse and nitric acid-generating wastewater treatment application.

Dendritic Mesoporous Silica Nanosphere-Embedded Polyacrylonitrile Electrospun Composite Nanofiltration Membrane with Crumpled Structure and High Water Permeance

“…The porous support substrate is traditionally fabricated by the phase inversion method, and the active surface layer could be facilely fabricated by interfacial polymerization (IP). , However, due to the “trade-off” effect of the polyamide (PA) active layer, the water permeability of the current NF membrane is still unsatisfied. In recent years, extensive efforts have been made to improve the water permeability: on the one hand, researchers try to adjust the structure of the support substrate; − on the other hand, researchers make efforts in regulating the structure of the PA layer. − …”