NMR, Electrical Relaxation, and High Pressure Electrical Conductivity in Ion Conducting Polymers

摘要

Recent nuclear magnetic resonance (NMR), electrical relaxation, and high pressure electrical conductivity studies of ion conducting polymers are reviewed. Most of the work discussed is that concerned with poly(ethylene oxide) (PEO) though some recent results concerning poly(vinyl acetate) are also described. A survey of experimental 1H, 7Li, 19F, and 23Na NMR data for ion conducting polymers based on PEO reveals some features that are commonly observed in supersonic solids, such as motional narrowing in the temperature region of enhanced conductivity. The NMR activation energies are generally lower than those for conductivity, indicating the presence of localized motional processes. Previous electrical relaxation data along with new results for PE04.5:NaI and PE04.5:LiCF3S03 make it clear that PEO complexed with different salts exhibits different electrical relaxation spectra. Changes in chain structure are detected along with multiphase behavior. Also, new results are presented for the effect of high pressure on the electrical conductivity of poly(propylene oxide) complexed with alkali metal salts. Those results eliminate some ambiguities associated with previous high pressure electrical conductivity studies of PEO.