Diffusion and dielectric studies of the system PPO4000–NH4CF3SO3
1999 (English)In: International Conference(12th) on Solid State Ionics Held in Kassandra, Halkidiki Thessaloniki, Greece on June 6-12, 1999, 1999Conference paper (Refereed)
A polymer electrolyte system composed of poly(propylene oxide) of molecular weight 4000 (PPO4000) complexed with NH4CF3SO3 (NH4TF) has been investigated by multinuclear pfg-NMR and AC impedance methods. Samples in the concentration range 0.03–0.69 mol/kg (O:NH4 ratios of 500:1–22:1) have been investigated over the temperature range 25–75°C. The combination of AC conductance and pfg-NMR diffusion measurements gives clear evidence that extensive ion-aggregation/clustering occurs at low salt concentrations. With increasing salt-content the Haven ratio, defined as Λcalc/Λexp, decreases from >100 to 2 when going from 0.03 to 0.69 mol/kg. Such gross deviations from the Nernst–Einstein relation (i.e. Λ ∝ D++D−) originate in extensively correlated motions of ions. We interpret the results in terms of labile salt-rich sub-domains being further destabilized through an increase in the dielectric constant of the solution with increasing salt content.
Place, publisher, year, edition, pages
Pfg-NMR, Diffusion, AC conductance
IdentifiersURN: urn:nbn:se:umu:diva-10025DOI: doi:10.1016/S0167-2738(00)00563-4OAI: oai:DiVA.org:umu-10025DiVA: diva2:149696
Solid State Ionics 2000, volumes 136-137, pages 457-612008-06-112008-06-11Bibliographically approved