Influence of hydrophobic components tuning of poly (aryl ether sulfone)s ionomers based anion exchange membranes on diffusion dialysis for acid recovery

Abstract

In this work, AEMs based on poly(arylene ether sulfone)s skeletons were tailored with three kinds of hydrophobic components: biphenol (BP) with conjugate double benzene rings , bisphenol A (BPA) containing isolated double benzene rings and fluorene-9-bisphenol (FBP) with Cardo ring skeleton of four benzene rings. A series of quaternized poly(arylene ether sulfone)s (QPAES) membranes were fabricated successfully including QPAES-BP, QPAES-BPA and QPAES-FBP. The obtained membranes were applied in diffusion dialysis (DD) process of simulated waste acid (1.0 mol L-1 HCl and 0.2 mol L-1 FeCl2) to figure out the influence of hydrophobic structures on DD performance. The dialysis coefficients (UH+) were in the range from 12.13 × 10-3 m h-1 to 13.28 × 10-3 m h-1, while the separation factors (S) were in the range from 67.33 to 126.37. The resultant membranes show much better performance compared with the commercial TWDDA1 membrane (UH+ = 8.5 × 10-3 m h-1, S = 18.5). Interestingly, the membrane structures and properties revealed that the rigid aromatic component induced low water swelling, strong mechanical property and microphase separation, the nature of the structure offers high UH+ as well as high S. The results show that the fabricated membranes are potential candidates for the acid recovery in diffusion dialysis, especially the QPAES-BP membrane tuned with rigid linear conjugated hydrophobic component.