| Yazarlar |
Yunus KARATAŞ
Ahi Evran Üniversitesi, Türkiye |
Radha D Banhatti
|
|
Nitin Kaskhedikar
|
|
Marina Burjanadze
|
|
Klaus Funke
|
|
Hans-Dieter WiemhöFer
|
| Özet |
| The effect of both nanoparticles and low molecular weight borate esters on the ionic conductivity of crosslinked polysiloxanes was systematically investigated by means of measuring conductivity spectra in the impedance regime at temperatures between -30 and 90 °C. Salt-in-polymer electrolytes were prepared by dissolving lithium triflate (LiSO3CF3) in comblike polysiloxanes bearing one methyl and one oligoether side group per silicon. An amount of 10 mol % of the oligoether side groups exhibited a terminal allytrimethoxysilane serving as a cross-linker moiety (T 0.1OPS). Thus prepared polymer electrolyte membranes were completely amorphous and mechanically stable with an optimum conductivity value of 5.7 x 10-5 S.cm-1 at 15 wt % of lithium triflate (LiSO 3CF3) at room temperature (T0.1OPS + 15 wt % LiSO3CF3). Further investigations concerned the influence of additives, i.e., nanosized ceramic fillers ((α-Al2O 3 and SiO2, up to 10 wt %) as well as two low molecular weight borate esters (tris(2-(2-methoxyethoxy)ethyl) borate (B2) and tris(2-(2-(2-methoxyethoxy)ethoxy)ethyl) borate (B3)) with maximum concentrations of 40 wt % as referred to polysiloxane T0.1OPS. The addition of borate esters resulted in a considerable increase of the conductivity, while still maintaining the mechanical stability. Optimum conductivities of 3.7 x 10-5 and 1.6 x 10-4S.Cm -1 were measured for B2 and B3, respectively, at room temperature. A fit of the temperature-dependent DC conductivity by the empirical Vogel-Tammann-Fulcher (VTF) equation showed that there was an increased number density of mobile charge carriers in the case of borate esters as additives. However, the shape of the conductivity spectra in the dispersive regime changed considerably in going from nanoparticles as additives to borate esters. A careful and consistent modeling of the conductivity spectra and of the temperature dependence of the DC conductivity was done within the framework of the MIGRATION concept. The result was that the addition of borate esters to the polymer host most probably increased both number density of mobile charge carriers as well as their mobility © 2009 American Chemical Society. |
| Anahtar Kelimeler |
| Makale Türü | Özgün Makale |
| Makale Alt Türü | SSCI, AHCI, SCI, SCI-Exp dergilerinde yayımlanan tam makale |
| Dergi Adı | The Journal of Physical Chemistry B |
| Dergi ISSN | 1520-6106 |
| Dergi Tarandığı Indeksler | SSCI |
| Makale Dili | İngilizce |
| Basım Tarihi | 11-2009 |
| Cilt No | 113 |
| Sayı | 47 |
| Sayfalar | 15473 / 15484 |
| Doi Numarası | 10.1021/jp907832q |
| Makale Linki | http://pubs.acs.org/doi/abs/10.1021/jp907832q |
