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Compositional effects on structure and transport properties in a polyelectrolyte gel

journal contribution
posted on 01.08.2002, 00:00 authored by Maria ForsythMaria Forsyth, H Every, D MacFarlane, J Travas-Sejdic, R Steiner
The copolymerization of lithium 2-acrylamido-2-methyl-1-propane sulfonate (LiAMPS) with N,N ′-dimethylacrylamide has yielded polyelectrolyte systems which can be gelled with an ethylene carbonate/N ′,N ′-dimethylacetamide solvent mixture and show high ionic conductivities. 7Li linewidth and relaxation times as well as 1H NMR diffusion coefficients have been used to investigate the effect of copolymer composition as well as copolymer concentration in the gel electrolyte with respect to ionic transport and polyelectrolyte structure. It appears that ion association is likely even in the case of low lithium salt concentration; however a rapid exchange exists between the associated and non-associated lithium species. Beyond 0.2 M of LiAMPS, both the conductivity and solvent diffusion reach a plateau, whilst lithium ion linewidth and spin-spin relaxation are suggestive, on average, of a less mobile species. The thermal analysis data is also supportive of this association effectively leading to a form of phase separation on the nanoscale, which gives a lower overall activity of lithium ions in the solvent rich regions beyond about 0.2 M of LiAMPS, thereby leading to an increase in the final liquidus temperature of the binary liquid solvent from –9 to +5°C.

History

Journal

Macromolecular materials and engineering

Volume

287

Issue

8

Pagination

523 - 531

Publisher

Wiley - VCH Verlag

Location

Weinheim, Germany

ISSN

1438-7492

eISSN

1439-2054

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2002, WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim