Advanced

Anion-conducting polysulfone membranes containing hexa-imidazolium functionalized biphenyl units

Weiber, Annika LU and Jannasch, Patric LU (2016) In Journal of Membrane Science 520. p.425-433
Abstract
Poly(arylene ether sulfone)s containing randomly distributed biphenyl units tethered with precisely six imidazolium cations are designed and prepared with the aim to facilitate ionic clustering and conductivity of anion exchange membranes (AEMs). A series of statistical copolymers with different cationic contents are synthesized via K2CO3-mediated polycondensations of 2,2′,3,3′,5,5′-hexamethyl-4,4′-dihydroxybiphenyl, bisphenol-A and 4,4′-dichlorodiphenylsulfone. After near quantitative benzylic brominations, the copolymers are functionalized with N-methylimidazolium (NIM), 1,2,4,5-tetramethylimidazolium (4IM) and trimethylammonium (QA) groups, respectively. Small angle X-ray scattering of AEMs cast from solution shows that all the... (More)
Poly(arylene ether sulfone)s containing randomly distributed biphenyl units tethered with precisely six imidazolium cations are designed and prepared with the aim to facilitate ionic clustering and conductivity of anion exchange membranes (AEMs). A series of statistical copolymers with different cationic contents are synthesized via K2CO3-mediated polycondensations of 2,2′,3,3′,5,5′-hexamethyl-4,4′-dihydroxybiphenyl, bisphenol-A and 4,4′-dichlorodiphenylsulfone. After near quantitative benzylic brominations, the copolymers are functionalized with N-methylimidazolium (NIM), 1,2,4,5-tetramethylimidazolium (4IM) and trimethylammonium (QA) groups, respectively. Small angle X-ray scattering of AEMs cast from solution shows that all the different hexa-functionalized moieties induce distinct phase separation. This is especially efficient in the NIM materials, which may be because the less bulky nature of this cation in comparison with 4IM. Thus, at a given water uptake the AEMs containing NIM reach a significantly higher conductivity than those with 4IM ions. In addition, AEMs containing any of the two hexa-imidazolium moieties reach higher conductivities than corresponding materials with hexa-QA moieties, which probably results from the delocalized charge of the former cations which promotes ionic dissociation despite very high local ionic concentrations. Introducing biphenyl units tethered with precisely six imidazolium cations along a copolymer backbone may be a viable synthetic strategy towards efficient AEMs for different electrochemical energy applications. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Membrane Science
volume
520
pages
425 - 433
publisher
Elsevier
external identifiers
  • scopus:84981489616
  • wos:000384785000042
ISSN
0376-7388
DOI
10.1016/j.memsci.2016.07.051
language
English
LU publication?
yes
id
f5e7d2b4-4aff-4fc4-afa5-0e1606fbbf9b
date added to LUP
2016-08-02 08:32:05
date last changed
2017-01-01 08:31:17
@article{f5e7d2b4-4aff-4fc4-afa5-0e1606fbbf9b,
  abstract     = {Poly(arylene ether sulfone)s containing randomly distributed biphenyl units tethered with precisely six imidazolium cations are designed and prepared with the aim to facilitate ionic clustering and conductivity of anion exchange membranes (AEMs). A series of statistical copolymers with different cationic contents are synthesized via K2CO3-mediated polycondensations of 2,2′,3,3′,5,5′-hexamethyl-4,4′-dihydroxybiphenyl, bisphenol-A and 4,4′-dichlorodiphenylsulfone. After near quantitative benzylic brominations, the copolymers are functionalized with N-methylimidazolium (NIM), 1,2,4,5-tetramethylimidazolium (4IM) and trimethylammonium (QA) groups, respectively. Small angle X-ray scattering of AEMs cast from solution shows that all the different hexa-functionalized moieties induce distinct phase separation. This is especially efficient in the NIM materials, which may be because the less bulky nature of this cation in comparison with 4IM. Thus, at a given water uptake the AEMs containing NIM reach a significantly higher conductivity than those with 4IM ions. In addition, AEMs containing any of the two hexa-imidazolium moieties reach higher conductivities than corresponding materials with hexa-QA moieties, which probably results from the delocalized charge of the former cations which promotes ionic dissociation despite very high local ionic concentrations. Introducing biphenyl units tethered with precisely six imidazolium cations along a copolymer backbone may be a viable synthetic strategy towards efficient AEMs for different electrochemical energy applications.},
  author       = {Weiber, Annika and Jannasch, Patric},
  issn         = {0376-7388},
  language     = {eng},
  pages        = {425--433},
  publisher    = {Elsevier},
  series       = {Journal of Membrane Science},
  title        = {Anion-conducting polysulfone membranes containing hexa-imidazolium functionalized biphenyl units},
  url          = {http://dx.doi.org/10.1016/j.memsci.2016.07.051},
  volume       = {520},
  year         = {2016},
}