Advanced

A practical method for measuring the ion exchange capacity decrease of hydroxide exchange membranes during intrinsic degradation

Kreuer, Klaus-Dieter and Jannasch, Patric LU (2018) In Journal of Power Sources 375. p.361-366
Abstract
In this work we present a practical thermogravimetric method for quantifying the IEC (ion exchange capacity) decrease of hydroxide exchange membranes (HEMs) during intrinsic degradation mainly occurring through nucleophilic attack of the anion exchanging group by hydroxide ions. The method involves measuring weight changes under controlled temperature and relative humidity. These conditions are close to these in a fuel cell, i.e. the measured degradation rate includes all effects originating from the polymeric structure, the consumption of hydroxide ions and the release of water. In particular, this approach involves no added solvents or base, thereby avoiding inaccuracies that may arise in other methods due to the presence of solvents... (More)
In this work we present a practical thermogravimetric method for quantifying the IEC (ion exchange capacity) decrease of hydroxide exchange membranes (HEMs) during intrinsic degradation mainly occurring through nucleophilic attack of the anion exchanging group by hydroxide ions. The method involves measuring weight changes under controlled temperature and relative humidity. These conditions are close to these in a fuel cell, i.e. the measured degradation rate includes all effects originating from the polymeric structure, the consumption of hydroxide ions and the release of water. In particular, this approach involves no added solvents or base, thereby avoiding inaccuracies that may arise in other methods due to the presence of solvents (other than water) or co-ions (such as Na+ or K+). We demonstrate the method by characterizing the decomposition of membranes consisting of poly(2,6-dimethyl-1,4-phenylene oxide) functionalized with trimethyl-pentyl-ammonium side chains. The decomposition rate is found to depend on temperature, relative humidity RH (controlling the hydration number λ) and the total water content (controlled by the actual IEC and RH). (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Hydroxide exchange membrane , Fuel cell, Thermogravimetry, Degradation, AEM
in
Journal of Power Sources
volume
375
pages
6 pages
publisher
Elsevier
external identifiers
  • scopus:85026660088
ISSN
1873-2755
DOI
10.1016/j.jpowsour.2017.07.106
language
English
LU publication?
yes
id
37ca6adf-eb26-43d0-9011-57df725eaf45
date added to LUP
2017-07-28 16:05:37
date last changed
2018-02-04 04:30:51
@article{37ca6adf-eb26-43d0-9011-57df725eaf45,
  abstract     = {In this work we present a practical thermogravimetric method for quantifying the IEC (ion exchange capacity) decrease of hydroxide exchange membranes (HEMs) during intrinsic degradation mainly occurring through nucleophilic attack of the anion exchanging group by hydroxide ions. The method involves measuring weight changes under controlled temperature and relative humidity. These conditions are close to these in a fuel cell, i.e. the measured degradation rate includes all effects originating from the polymeric structure, the consumption of hydroxide ions and the release of water. In particular, this approach involves no added solvents or base, thereby avoiding inaccuracies that may arise in other methods due to the presence of solvents (other than water) or co-ions (such as Na<sup>+</sup> or K<sup>+</sup>). We demonstrate the method by characterizing the decomposition of membranes consisting of poly(2,6-dimethyl-1,4-phenylene oxide) functionalized with trimethyl-pentyl-ammonium side chains. The decomposition rate is found to depend on temperature, relative humidity RH (controlling the hydration number λ) and the total water content (controlled by the actual IEC and RH).},
  author       = {Kreuer, Klaus-Dieter and Jannasch, Patric},
  issn         = {1873-2755},
  keyword      = {Hydroxide exchange membrane ,Fuel cell,Thermogravimetry,Degradation,AEM},
  language     = {eng},
  pages        = {361--366},
  publisher    = {Elsevier},
  series       = {Journal of Power Sources},
  title        = {A practical method for measuring the ion exchange capacity decrease of hydroxide exchange membranes during intrinsic degradation},
  url          = {http://dx.doi.org/10.1016/j.jpowsour.2017.07.106},
  volume       = {375},
  year         = {2018},
}