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.
POLY(ETHYLENE OXIDE)
sol-gel
COMPLEXES
RAMAN-SPECTRA
ORMOLYTES
LIQUID
FT-Raman spectroscopy
LITHIUM PERCHLORATE
INFRARED TEMPERATURE
OXIDATION
FT-IR
POLYMER ELECTROLYTE
LiTFSI
PHYSICAL-PROPERTIES
di-ureasils
Author
S. C. Nunes
University of Trás-os-Montes and Alto Douro
V. D. Bermudez
University of Trás-os-Montes and Alto Douro
Denis Ostrovskii
Chalmers, Applied Physics, Condensed Matter Physics
P. C. Barbosa
University of Minho
M. M. Silva
University of Minho
M. J. Smith
University of Minho
Chemical Physics
0301-0104 (ISSN)
Vol. 345 1 32-40Subject Categories
Other Engineering and Technologies
DOI
10.1016/j.chemphys.2008.01.034