Cationic and anionic environments in LiTFSI-doped di-ureasils with application in solid-state electrochromic devices
Journal article, 2008
Fourier Transform mid-infrared and Raman spectroscopies were used to investigate the cation/polymer, cation/urea bridge, cation/anion and hydrogen bonding interactions in poly(oxyethylene) (POE)/siloxane di-ureasil networks prepared by the sol-gel route and doped with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). Materials with compositions 200 >= n >= 5 (where n expresses the molar ratio OCH2CH2/Li+) were studied. The Li+ ions coordinate to the urea carbonyl oxygen atoms over the whole range of salt concentration considered. Bonding to the ether oxygen atoms of the POE chains occurs at n <= 40, although a significant fraction of the POE chains remain non-coordinated. In these high salt content samples, the cations interact with the anions forming contact ion pairs. "Free" ions are probably the main charge carriers at the room temperature conductivity maximum of these ormolytes. (C) 2008 Elsevier B.V. All rights reserved.
ORMOLYTES
di-ureasils
POLY(ETHYLENE OXIDE)
INFRARED TEMPERATURE
LITHIUM PERCHLORATE
sol-gel
LiTFSI
OXIDATION
LIQUID
FT-IR
POLYMER ELECTROLYTE
RAMAN-SPECTRA
COMPLEXES
FT-Raman spectroscopy
PHYSICAL-PROPERTIES
Author
S. C. Nunes
Universidade de Tras-os-Montes e Alto Douro
V. D. Bermudez
Universidade de Tras-os-Montes e Alto Douro
Denis Ostrovskii
Chalmers, Applied Physics, Condensed Matter Physics
P. C. Barbosa
Universidade do Minho
M. M. Silva
Universidade do Minho
M. J. Smith
Universidade do Minho
Chemical Physics
0301-0104 (ISSN)
Vol. 345 1 32-40Subject Categories (SSIF 2011)
Other Engineering and Technologies
DOI
10.1016/j.chemphys.2008.01.034