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- Adebahr, Josefina, 1973, et al.
(författare)
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Enhancement of ion dynamics in PMMA-based gels with addition of TiO2 nano-particles
- 2003
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Ingår i: Electrochimica Acta. - 0013-4686. ; 48:14-16, s. 2099-2103
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Tidskriftsartikel (refereegranskat)abstract
- Solvent and ion dynamics in PMMA based gels have been investigated as a function of the loading of nanosized TiO 2 particles. The gels have a molar ratio of 46.5:19:4.5:30 of ethylene carbonate (EC), propylene carbonate (PC), lithium perchlorate and PMMA, respectively. A series of samples with 0, 4, 6 and 8 wt.% TiO 2 filler were investigated. The diffusion coefficients for the lithium ions and for the two solvents (EC and PC) were investigated by pfg-NMR. It was shown that the addition of filler to the gel electrolytes enhances the diffusion of the cations, while the diffusion of the solvents remains constant. Raman measurements show no significant changes in ion-ion interactions with the addition of fillers, while the ionic conductivity is seen to decrease. However, the sample with 8 wt.% TiO 2 had a conductivity close to that of the unfilled sample. © 2003 Elsevier Science Ltd. All rights reserved.
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| 2. |
- Adebahr, Josefina, 1973, et al.
(författare)
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Ion transport in polymer electrolytes containing nanoparticulate TiO2: The influence of polymer morphology
- 2003
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Ingår i: Physical Chemistry Chemical Physics. - : Royal Society of Chemistry (RSC). - 1463-9084 .- 1463-9076. ; 5:4, s. 720-725
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies have shown that composite polymer electrolytes, formed by dispersing nanosized ceramic particles in polyether-based electrolytes, have improved ion transport properties as compared to their unfilled analogues. In the present study polymer electrolytes with different loadings of nano-sized ceramic particles (TiO 2 ) and different polymer chemistry and morphology have been investigated. Of special interest are filler induced effects on polymer, solvent and cationic mobility. Partly crystalline polymer electrolytes based on poly(ethylene oxide) have been compared to fully amorphous polymer electrolytes based on a polyether urethane, as well as gel electrolytes based on PMMA. 7 Li pfg-NMR, linewidth and spin-spin relaxation times as well as 1 H pfg-NMR and spin-spin relaxation times, were measured as a function of temperature and composition. The 1 H spin-spin relaxation measurements reveal increased average polymer mobility with the addition of filler up to a maximum at 4 and 8 wt.% TiO 2 for the fully amorphous and the partly crystalline electrolytes, respectively. The 7 Li linewidth measurements for the fully amorphous system show a broadening of the linewidth with addition of filler. Based on variable temperature measurements this broadening is interpreted as a result of the inhomogeneity introduced by the filler particles. Pulsed field gradient (pfg) diffusion measurements were employed to determine ion and solvent self-diffusion coefficients. In the case of the PMMA-based gel electrolyte and the fully amorphous electrolytes enhanced cation self-diffusion was observed upon addition of TiO 2 .
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