Artículos de revistas
Local and nanoscopic structure of potassium triflate-doped siloxane-polyoxyethylene ormolytes
Fecha
2006-09-15Registro en:
Journal of Non-crystalline Solids. Amsterdam: Elsevier B.V., v. 352, n. 32-35, p. 3457-3462, 2006.
0022-3093
10.1016/j.jnoncrysol.2006.02.109
WOS:000240706000015
5584298681870865
9971202585286967
0000-0002-8356-8093
Autor
Universidade Estadual Paulista (Unesp)
Univ Tras Os Montes
Ctr Univ Paris Sud
SOLEIL
Universidade de São Paulo (USP)
Institución
Resumen
Siloxane-poly(oxyethylene) hybrids obtained by the sol-gel process and containing short polymer chain have been doped with potassium triflate (KCF3SO3). The local structure of these hybrids was investigated by X-ray absorption spectroscopy near the potassium K-edge. Small angle X-ray scattering was used to determine the structure at the nanometer scale. Results revealed that at low and medium potassium concentration (n = [O][K] >= 8, where n represents the molar ratio of ether-type oxygen atoms per alkaline cation) the cations interact mainly with the polymer chains, while at larger doping level (n < 8) the formation of a polyehter:KCF3SO3 Complex is observed. The nanoscopic structure of the hybrids is also affected by doping. By increasing the doping level, decreasing trends in the electronic density contrast between siloxane nanoparticles and polyether matrix and in the siloxane interparticle distance are observed. At high doping level the small angle X-ray scattering patterns are strongly modified, showing the disappearance of the correlation peak and the formation of a potassium-containing nanophase. (c) 2006 Elsevier B.V. All rights reserved.