R. Bergman et al., PHOTON-CORRELATION STUDY OF STRUCTURAL RELAXATIONS IN NACF3SO3 CONTAINING POLYMER ELECTROLYTES, Journal of non-crystalline solids, 172, 1994, pp. 830-837
The structural relaxation characteristics of NaCF3SO3 complexed poly (
propylene-glycol) (PPG) have been investigated using photon correlatio
n spectroscopy. Addition of NaCF3SO3 to PPG results in a considerable
slowing of the relaxation dynamics and a broadening of the width of th
e observed density correlation function. The relaxation time spectrum
provides clear evidence of two relaxation processes separated in time
and with a relative strength depending on temperature and concentratio
n of the dopant salt. Both processes are attributed to segmental motio
ns of the polymer chains; the slower relaxation to segments that are t
ransiently crosslinked by the solvated cations; the faster process to
motions of 'free' segments away from the crosslinks. The results are d
iscussed in relation to models developed to explain the conductivity m
echanism in polymer electrolytes.