A facile approach to prepare crosslinked polysulfone-based anion exchange membranes with enhanced alkali resistance and dimensional stability. Issue 62 (8th November 2019)

• Record Type: Journal Article
• Authors: Wang, Chao; Pan, Nengxiu; Jiang, Yuliang; Liao, Junbin; Sotto, Arcadio; Ruan, Huimin; Gao, Congjie; Shen, Jiangnan
• Is Part Of: RSC advances. Volume 9:Issue 62(2019)
• Page Start: 36374
• Page End: 36385
• Publication Date: 2019-11-08
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c9ra07433c
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Novel anion exchange membranes with enhanced ion exchange capacity, dimensional stability and alkali stability were prepared by a facile synthesis method. Abstract : Novel anion exchange membranes with enhanced ion exchange capacity, dimensional stability and alkali stability were prepared by a facile synthesis method. Internal crosslinking networks in the resulting membranes were achieved by reacting chloromethylated polysulfone with 4, 4′-trimethylene bis(1-methylpiperidine) (BMP), where BMP was used as both a quaternization reagent and crosslinker without requirement of post-functionalization. In order to evaluate the alkali resistance and dimension stability performance of the resulting membranes, the molar ratio of BMP in the resulting membranes was fixed at four different contents: 40%, 60%, 80% and 100%. The obtained membranes were accordingly denoted as CAPSF- N, in which N = 40, 60, 80 and 100, respectively. Due to the dense internal network structure and spatial conformation of the six-membered rings, the resulting CAPSF- N AEMs showed enhanced dimensional structures (at 60 °C, the water uptakes and swelling ratios of CAPSF- N were 8.42% to 14.84% and 2.32% to 5.93%, respectively, whereas those for the commercial AEM Neosepta AMX were 44.23% and 4.22%, respectively). In addition, after soaking in 1 M KOH solution at 60 °C for 15 days, the modified membranes exhibited excellent alkaline stability. The CAPSF-100 membrane showed the highest alkali stability (retained 85% of its original ion exchange capacity and 84% of its original OH − conduction after the alkaline stability test), whereas the non-crosslinked APSF broke into pieces. Additionally, compared to the commercial Neosepta AMX membrane under the same test conditions, the desalination efficiency of CAPSF-100 was enhanced, and the energy consumption was lower.