Artigo
Effect of salt nature on structure and ionic conductivity of sodium-doped siloxane-PPO ormolytes
Fecha
2005-01-01Registro en:
Journal of the European Ceramic Society. Oxford: Elsevier B.V., v. 25, n. 12, p. 2617-2621, 2005.
0955-2219
10.1016/j.jeurceramsoc.2005.03.113
WOS:000230569300133
5584298681870865
9971202585286967
0000-0002-8356-8093
Autor
Universidade Estadual Paulista (Unesp)
Ctr Univ Paris Sud
Universidade de São Paulo (USP)
Resumen
Siloxane-polyoxypropylene (PPO) hybrids obtained by the sol-gel process and containing short polymer chain have been doped with different sodium salts NaX (X = ClO4, BF4 or I). The effect of the counter-ion (X) on the chemical environment of the sodium ions and on the ionic conductivity of these hybrids was investigated by Na-23 NMR, small angle X-ray scattering (SAXS), complex impedance, Raman spectroscopy and differential scanning calorimetry (DSC). Results reveal that the different sodium salts have essentially the same effect on the nanoscopic structure of the hybrids. The formation of immobile Na+ cations involved in NaCl-like species could be minimized by using a low amount of HCl as hydrolytic catalyst. The differences in the ionic conductivity of hybrids doped with different sodium salts were correlated with the proportion of Na ions solvated by ether-type oxygen of the polymeric chains and by the carboxyl oxygen located in the urea groups of the PPO chain extremities. (c) 2005 Elsevier Ltd. All rights reserved.