Fig. 2: Membrane synthesis and characterization.
From: Monovalent anion-selective membranes fabricated via in situ interfacial polymerization
a Synthetic pathway for PAB polymer, NML-Qx membranes, and NML-Qx-NH2 membranes. Membranes (Cl− form) were subjected to ISIP surface modification, which occurs only on the membrane surface while the internal structure remains unchanged. b ¹H NMR spectra of the synthesized polymer (solvent: DMSO‑d6, 400 MHz), with detailed peak assignments corresponding to specific chemical structures, confirming the successful incorporation of desired functional groups. c ATR-FTIR spectra highlighting the key components of the quaternized membranes, including NML-Q3, NML-Q3-NH2, and the polyamide (PA) layer. The spectra provide evidence of successful functionalization and chemical modification at the membrane surface. d XPS survey spectra displaying the surface chemical composition of the NML, NML-Q3, and NML-Q3-NH2 membranes, confirming the presence and distribution of quaternized groups and amine functionalization on the membrane surface.
