Dimensionally stable hexamethylenetetramine functionalized polysulfone anion exchange membranes. Issue 29 (20th June 2017)

• Record Type: Journal Article
• Authors: Chen, Wanting; Hu, Mengmeng; Wang, Haochen; Wu, Xuemei; Gong, Xue; Yan, Xiaoming; Zhen, Dongxing; He, Gaohong
• Is Part Of: Journal of materials chemistry. Volume 5:Issue 29(2017)
• Page Start: 15038
• Page End: 15047
• Publication Date: 2017-06-20
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c7ta01218g
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Hexamethylenetetramine mono-quaternized polysulfone AEM (2.23 mmol g −1 ) exhibits a low swelling ratio (21% at 60 °C) due to strong electrostatic interactions. Abstract : A novel alkaline group, hexamethylenetetramine (HMTA) with four tertiary amine groups and β-hydrogen-absent structure, has been employed as mono-quaternization reagent to prepare HMTA mono-quaternized polysulfone anion exchange membranes (PSF-QuOH AEMs). Analyzed by molecular dynamics simulations, mono-quaternized HMTA shows a superior aggregating ability by strong electrostatic interaction with hydroxide to suppress water swelling even at high IECs. In particular, the PSF-QuOH membrane with a high IEC of 2.23 mmol g −1 exhibits a low swelling ratio of 21% even at 60 °C. The resulting high concentration of cationic groups and the interactions between multiple hydrogen atoms in HMTA and hydroxide/water are helpful to induce the formation of the continuous and efficient hydrogen-bond networks, promoting ionic transport. High hydroxide conductivity of 35 mS cm −1 is achieved at 20 °C. Excellent swelling resistance also benefits the mechanical and chemical stabilities of the PSF-QuOH membranes. A considerable mechanical strength of 17.7 MPa is observed in the fully hydrated membrane. The hydroxide conductivity is stable at around 86% of the initial value after 1 M KOH immersion at 60 °C for 168 h.