Specific conductivity of lithium perclorate dissolved in poly (ethylene glycol-400) distereate

Oliveira, A.L. de; Damasceno, O. de O.; Silva, P.R.; Sangiorge, C.L.; Armand, Michel; Kleitz, M.

doi:10.1016/0167-2738(93)90281-7

Cited by 6 publications

(13 citation statements)

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“…This order-disorder transition around y ) 9 occurs at the same lithium concentration as the previously observed peak in ionic conductivity at 50 °C. [1][2][3][4][5] Figure 4 shows the temperature dependence of the SAXS diffraction intensities around 2.1°for the pure and doped samples (y ) 5, 7, 9, 12, and 16). As can be seen for samples with y g 9, the SAXS patterns show weak and broad lines (disorder) well above the melting temperature (35 °C).…”

Section: Resultsmentioning

confidence: 99%

“…1 H NMR. 1 H NMR is also useful for characterizing the polymer host dynamics. The static direct-polarization 1 H NMR spectra for the Li + -doped (y ) 5) PEGD sample, shown in Figure 16, were recorded for several temperatures above the melting point, from 37 to 90 °C.…”

Section: Resultsmentioning

confidence: 99%

“…These results support the use of an order-disorder model 4,5 to explain the previously reported dependence of ionic conductivity on Li + concentration in these samples. 1…”

Section: Discussionmentioning

confidence: 99%

“…To obtain the desired ratios of oxygen to Me + , the complexes were prepared by direct dissolution at 80 °C under vigorous stirring of appropriate amounts of LiClO4 or NaClO4 in PEGD. 1 The Li + -and Na +doped PEGD samples were prepared with y ) 5, 6, 7, 8, 9, 10, 11, 12, and 50. Immediately after preparation, the samples † USP.…”

Section: Methodsmentioning

confidence: 99%

“…4 The alkali metal ion (Li + or Na + ) concentration dependence of the ionic conductivity at 50 °C (above the polymer melting point) goes through a very sharp peak, where the ionic conductivity reaches values of approximately 8.0 × 10 -4 S/cm (for Li + -PEGD) and 1.3 × 10 -4 S/cm (for Na + -PEGD) for y ) 9. 1,4,5 For these ABA triblock ionic conducting copolymers, a special model was proposed on the basis of the order-disorder transition to explain the ionic conductivity behavior as a function of the alkali metal ion concentration above the melting point. 4,5 To further explore this model, we have performed 1 H, 7 Li, 13 C, and 23 Na solid-state NMR measurements on PEGD doped with Li + and Na + with several O/Me + ratios.…”

Section: Introductionmentioning

confidence: 99%

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Phase Behavior and Dynamics of the ABA Triblock Copolymer Poly(ethylene glycol) Distearate Doped with Alkali Metal Salts

et al. 2002

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The ABA triblock copolymer poly(ethylene glycol) distearate (PEGD), average M n ca. 930, complexed with lithium and sodium perchlorates has been studied by 1H, 7Li, 13C, and 23Na solid-state nuclear magnetic resonance (NMR), SAXS, DSC, and polarized-light optical microscopy. Unlike other solid polymer electrolytes, highly Li+-doped PEGD samples exhibit sharp 7Li NMR quadrupolar powder patterns even at temperatures well above the melting point, indicating that this triblock copolymer is microphase separated and the dynamics in the PEG phase are anisotropic. Measurements of the 7Li central transition line width in highly doped samples show three distinct line narrowings, due to the poly(ethylene glycol) glass transition (∼−20 °C), the stearate melting point of the polymer (∼35 °C), and an order−disorder transition (∼72 °C). 23Na NMR measurements yield similar results. SAXS, DSC, and optical microscopy with polarized light confirm the presence of a microphase-separated state up to ∼72 °C. 13C and 1H NMR show that the segmental mobility in the ordered state is reduced compared to the isotropic melt. The results confirm the previously proposed order−disorder model to explain the dependence of the ionic conductivity on the lithium concentration for Li+-doped PEGD samples.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

“…These results support the use of an order-disorder model 4,5 to explain the previously reported dependence of ionic conductivity on Li + concentration in these samples. 1…”

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%