Studies of cation-anion and cation-polymer association in poly(ethylene oxide): Pb(CF3SO3)2 complexes

被引：0

作者：

Rhodes, Christopher P. ^{[1
]}

Kiassen, Barry ^{[1
]}

Frech, R. ^{[1
]}

Dai, Y. ^{[2
]}

Greenbaum, S.G. ^{[3
]}

机构：

[1] Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019, United States

[2] International Paper Company, Corporate Research Center, Tuxedo, NY 10987, United States

[3] Department of Physics, Hunter College, City University of New York, New York, NY 10021, United States

来源：

Solid State Ionics | 1999年 / 126卷 / 03期

基金：

美国国家航空航天局;

关键词：

Infrared spectroscopy - Lead compounds - Negative ions - Nuclear magnetic resonance spectroscopy - Phase transitions - Polyethylene oxides - Positive ions - Raman spectroscopy - Salts - Thermal effects;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

Solid polymer electrolytes consisting of poly(ethylene oxide) (PEO) and Pb(CF3SO3) were investigated by vibrational (Raman and infrared) and 207Pb nuclear magnetic resonance (NMR) spectroscopies. The vs(SO3) symmetric stretch and Δ(CF3) deformation vibrational modes both yield information on cation-anion association effects, while the CH2 rocking mode is very sensitive to cation-polyether oxygen interactions. The free ion concentration decreases with increasing temperature, as commonly observed for many other polymer electrolyte systems. In the present case, the largest decrease occurs in the temperature interval between 60° and 70°C, coinciding with melting of the pure PEO phase in the material. However, significant changes in polymer segmental conformation are also observed beginning around 50°C. Both temperature ranges in which the vibrational results exhibit large changes (50-60° and 60-70°C) also show substantial but separate transformations of the 207Pb NMR chemical shift interaction, which is dominated by cation-oxygen association. Both spectroscopic methods, which are sensitive to dynamic processes occurring on vastly different time scales, are nevertheless consistent in demonstrating the presence of at least two steps in the transition between the low temperature, partially crystalline phase and the high temperature, amorphous phase.

引用

页码：251 / 257