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Ether spaced N-spirocyclic quaternary ammonium functionalized crosslinked polysulfone for high alkaline stable anion exchange membranes.
- Source :
-
Journal of Membrane Science . Mar2020, Vol. 598, pN.PAG-N.PAG. 1p. - Publication Year :
- 2020
-
Abstract
- N-spirocyclic cations containing anion exchange membranes (AEMs) possess excellent alkaline stability, but poor mechanical and conductive properties due to the rigid N-spirocyclic structure and lack of flexible side chain structural design. In this work, a flexible ether spaced N-spirocyclic quaternary ammonium functionalized side chain is proposed, in which hydroxyl substituted N-spirocyclic cation provides active grafting site with chloromethylated polysulfone through Williamson etherification. The flexible ether-oxygen spacer promotes aggregation of the rigid spirocyclic cations and thus significantly improves conductivity. The uniformly in-situ thermal crosslinking between benzene rings and the residue chloromethyl groups in polysulfone greatly enhances mechanical properties of the membranes. Constrained ring conformation of N-spirocyclic cation, ether spaced benzyl-free side chain, as well as the OH− blocking crosslinked networks endow an excellent alkaline stability to the membranes. The ether spaced N-spirocyclic containing membranes exhibit well micro-phase separation structure, up to around 85.7 mS cm−1 of hydroxide conductivity at 80 oC, around 10.5 MPa of tensile strength in hydrated state and around 95.6% conductivity retention after immersion in 1 M KOH at 80 oC for 720 h. The performance is among the best N-spirocyclic functionalized AEMs reported in the literature. Image 1 • Crosslinked AEMs with ether spaced N-spirocyclic cationic side chain are proposed. • Flexible ether spacer promotes rigid spirocyclic cations to aggregate into cluster. • In-situ thermal treatment provides crosslinking networks for mechanical properties. • Benzyl-free spirocyclic cation and OH− blocked crosslinking endow alkaline stability. [ABSTRACT FROM AUTHOR]
- Subjects :
- *SULFONES
*CHLOROMETHYL group
*ANIONS
*ETHERS
*FLEXIBLE structures
*STRUCTURAL design
Subjects
Details
- Language :
- English
- ISSN :
- 03767388
- Volume :
- 598
- Database :
- Academic Search Index
- Journal :
- Journal of Membrane Science
- Publication Type :
- Academic Journal
- Accession number :
- 141639091
- Full Text :
- https://doi.org/10.1016/j.memsci.2019.117650