期刊
JOURNAL OF PHYSICAL CHEMISTRY B
卷 108, 期 20, 页码 6295-6302出版社
AMER CHEMICAL SOC
DOI: 10.1021/jp0499777
关键词
-
Broadband dielectric spectroscopy was used to investigate the segmental dynamics and ionic conduction in LiClO4/PVME complexes with Li/O from 0.1/100 to 10/100, at temperatures from T-g to similar toT(g) + 80 degreesC. Although no microphase separation is observed via DSC, dielectric experiments reveal two segmental relaxations and one localized ion motion process. The fastest process is attributed to relaxations of segments in ion-depleted domains and it slows down with increasing salt content, as does the ion motion. The segmental relaxation of PVME chains in ion-rich domains is even slower than the ion motion process, and about 104 times slower than the fast segmental process in the 0.5/100 complex. This process becomes faster with increasing LiClO4 content, despite the concurrent increase in the bulk Tg. Maximum molar conductivity is obtained in the 2/100 complex and the ionic conduction is about 10(-9) S/cm at 30 degreesC. By using the dynamic bond percolation model, it was found that the ions move about 0.8 nm for the 0.5/100 complex at 25 degreesC at the time scale of the slow segmental relaxation, assuming that structural renewal is realized by the latter. This size, together with the strong correlation between the ionic conduction and the slow segmental relaxation, supports the idea that hopping from one segment to another one is probably the effective fundamental step giving rise to macroscopic conduction.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据