Alkaline stability and ion conductivity of polysulfone anion exchange membranes (AEMs) with different cation chemistries

Christopher G. Arges, Vijay Ramani

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Scopus citations

Abstract

The use of several different NMR techniques (1H, 13C, 31P, 1H decoupled phosphorus, COSY, and 1H-X (X= 13C or 31P) HMQC) were employed to elucidate the chemical structure of degraded polysulfone (PSF) anion exchange membranes (AEMs) exposed to alkaline solutions. The NMR spectra revealed degradation products perpetrated by rearrangement reactions from ylide intermediates and direct nucleophilic attack for trimethylammonium (TMA+), 1,4-dimethylpiperazinium (DMP+), 1-methylimidazolium (1M+) and trimethylphosphonium (TMP+) cations. Stevens rearrangement was the only verified rearrangement reaction for the ammonium cations. Trimethylphosphonium PSF AEMs were observed to degrade through Somelet-Hauser rearrangement. The stability experiments demonstrated that the ylide mechanisms were more prevalent at lower concentrations of alkaline solutions (e.g. 1 M Na2CO3 and 1 M KOH) when compared to higher concentrations (e.g. 6 M KOH). Also, the NMR spectra provided evidence that the introduction of alkaline stable cation sites on PSF leads to ether hydrolysis of the backbone.

Original languageEnglish (US)
Title of host publicationPolymer Electrolyte Fuel Cells 12, PEFC 2012
PublisherElectrochemical Society Inc.
Pages2183-2197
Number of pages15
Edition2
ISBN (Print)9781607683506
DOIs
StatePublished - 2013
Event12th Polymer Electrolyte Fuel Cell Symposium, PEFC 2012 - 222nd ECS Meeting - Honolulu, HI, United States
Duration: Oct 7 2012Oct 12 2012

Publication series

NameECS Transactions
Number2
Volume50
ISSN (Print)1938-5862
ISSN (Electronic)1938-6737

Other

Other12th Polymer Electrolyte Fuel Cell Symposium, PEFC 2012 - 222nd ECS Meeting
Country/TerritoryUnited States
CityHonolulu, HI
Period10/7/1210/12/12

All Science Journal Classification (ASJC) codes

  • Engineering(all)

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