TY - JOUR
T1 - Complex impedance and multifrequency 23Na NMR study of poly (propylene oxide) complexed with NaB (C6H5)4
AU - Pak, Y. S.
AU - Adamic, K. J.
AU - Greenbaum, S. G.
AU - Wintersgill, M. C.
AU - Fontanella, J. J.
AU - Coughlin, Christopher
PY - 1991/1/1
Y1 - 1991/1/1
N2 - Complex impedance and multifrequency 23Na nuclear magnetic resnoance (NMR) measurements on a poly (propylene oxide): sodium tetraphenylborate, PPO8NaB(C6H5)4, solid polymer electrolyte, with a composition of eight ether oxygens per sodium, are reported. The NMR linewidths are found to be second-order quadrupole broadened, thus indicating low site-symmetry for the Na+ ions. The title compound exhibits some interesting differences in properties compared to other PPO-Na salt complexes, including an anomalously low value of the stretched exponential parameter ßse (obtained in fits to electric modulus data), an unusually high glass transition temperature (Tg=306 K), and sub-Tg line narrowing of lower frequency 23Na resonances. This last phenomenon is attributed to strong interaction between the Na+ ions and their large [B(C6H5)4]- counterions caused by the localization of the [B(C6H5)4]- anions in weak interactions with the polymer chains which, in turn, leads to the elevated glass transition temperatures.
AB - Complex impedance and multifrequency 23Na nuclear magnetic resnoance (NMR) measurements on a poly (propylene oxide): sodium tetraphenylborate, PPO8NaB(C6H5)4, solid polymer electrolyte, with a composition of eight ether oxygens per sodium, are reported. The NMR linewidths are found to be second-order quadrupole broadened, thus indicating low site-symmetry for the Na+ ions. The title compound exhibits some interesting differences in properties compared to other PPO-Na salt complexes, including an anomalously low value of the stretched exponential parameter ßse (obtained in fits to electric modulus data), an unusually high glass transition temperature (Tg=306 K), and sub-Tg line narrowing of lower frequency 23Na resonances. This last phenomenon is attributed to strong interaction between the Na+ ions and their large [B(C6H5)4]- counterions caused by the localization of the [B(C6H5)4]- anions in weak interactions with the polymer chains which, in turn, leads to the elevated glass transition temperatures.
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U2 - 10.1016/0167-2738(91)90162-5
DO - 10.1016/0167-2738(91)90162-5
M3 - Article
AN - SCOPUS:0026142475
VL - 45
SP - 277
EP - 284
JO - Solid State Ionics
JF - Solid State Ionics
SN - 0167-2738
IS - 3-4
ER -