| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1401883 | European Polymer Journal | 2014 | 8 Pages |
•Nafion-1035 films were complexed with the following ions: Na +, Li+, K+, and Ca2+.•Thermal stability temperature increased with metal ion type versus Nafion-H+.•Tg and reduction relaxation behavior was greatest for Nafion-Ca2+.•WAXD revealed no inter-chain changes within Nafion based upon ion size or valence.•P, D, S, EP, ED, and HS were reduced with metal-ion, but not systematically.
The physical and transport properties of Li+, Na+, K+, and Ca2+ neutralized Nafion were compared to its acid form. Nafion crystallinity was disrupted with a variety of cations while average d-spacing remained constant. Higher thermal stability in metal ion exchanged Nafion was observed using TGA. Ionic interactions were probed by DMA and spectroscopic techniques. Divalent Ca2+ exhibited a distinctive influence on the chain’s mobility as compared to monovalent ions. The interaction strength cation exchanged Nafion decreased in the following order: Li+ > Ca2+ > Na+ > K+. Gas permeability increases were primarily attributed to gas solubility. Nafion had a higher gas activation energy Ep, but its permeability was lower than unsulfonated PTFE.
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