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Correlations of Ion Motion and Chain Motion in Salt in Polysiloxane g oligoether Electrolytes     
Yazarlar
Miriam Kunze
 Yunus KARATAŞ Yunus KARATAŞ
Ahi Evran Üniversitesi, Türkiye
Hans-Dieter Wiemhöfer
Monika Schönhoff
Özet
The transport properties of salt and chains in a salt-in-polymer electrolyte consisting of polysiloxane-g-oligoether with different concentrations of lithium triflate, LiSO 3CF 3, are investigated. Temperature-dependent impedance spectroscopy, viscosity, and multinuclear self-diffusion NMR characterize the mobility of the chains and the different salt species, i.e., ion pairs or single ions. Comparison of different transport parameters allows conclusions about the motions of different species and correlations between them. For example, comparing diffusion coefficients and conductivities via the Nernst-Einstein equation, the fraction of undissociated ion pairs is concluded to be larger than 90%. Macroscopic and microscopic viscosities describe chain and small species motions, respectively. Distinct differences are observed between the temperature-dependence of the transport parameters of ion pairs, which is of Arrhenius-type, and that of the transport of chains or single ions, which deviates from Arrhenius, indicating a strong correlation with the chain dynamics for the latter. Most interestingly, the comparison of conductivity and fluidity data shows that their temperature dependence can be fully superimposed to a master curve in an Arrhenius plot, if shifted by a small value Δ(1/T) along the inverse temperature axis. This novel master curve scaling is a proof of the strong correlation of matrix and charge carrier dynamics. It is observed here for the first time in a macromolecular system, with the shift value Δ(1/T) as a quantity describing the correlation. © 2012 American Chemical Society.
Anahtar Kelimeler
Makale Türü Özgün Makale
Makale Alt Türü SSCI, AHCI, SCI, SCI-Exp dergilerinde yayımlanan tam makale
Dergi Adı Macromolecules
Dergi ISSN 0024-9297
Dergi Tarandığı Indeksler SSCI
Makale Dili İngilizce
Basım Tarihi 10-2012
Cilt No 45
Sayı 20
Sayfalar 8328 / 8335
Doi Numarası 10.1021/ma3014405
Makale Linki http://pubs.acs.org/doi/abs/10.1021/ma3014405