Artículos de revistas
XPS study on water corrosion of fluorzirconate glasses and their protection by a layer of surface modified tin dioxide nanoparticles
Fecha
2007-05-01Registro en:
Journal of Electron Spectroscopy and Related Phenomena. Amsterdam: Elsevier B.V., v. 156, p. 128-134, 2007.
0368-2048
10.1016/j.elspec.2006.11.013
WOS:000246726300275
WOS:000246726300081
6466841023506131
9971202585286967
5584298681870865
0000-0002-3823-0050
0000-0002-8356-8093
Autor
Universidade Estadual Paulista (Unesp)
Rhodia Polimida & Especialidades
Institución
Resumen
The surface corrosion process associated with the hydrolysis of fluorozirconate glass, Z-BLAN (53ZrF(4), 20BaF(2), 20NaF, 4LaF(2), 3AlF(3)), and the corrosion protection efficiency of a nanocrystalline transparent SnO2 layer were investigated by X-ray photoelectron spectroscopy. The tin oxide film was deposited by the sol-gel dip-coating process in the presence of Tiron(R) as particle surface modifier agent. The chemical bonding structure and composition of the surface region of coated and non-coated ZBLAN were studied before water contact and after different immersion periods (5-30 min). In contrast to the effects occurring for non-coated glass, where the surface undergoes a rapid selective dissolution of the most soluble species inducing the formation of a new surface phase consisting of stable zirconium oxyfluoride, barium fluoride and lanthanum fluoride species, the results for the SnO2-coated glass showed that the hydrolytic attack induces a filling of the film nanopores by dissolved glass material and the formation of tin oxylluoride and zirconium oxyfluoride species. This process results in a modified film, which acts as a hermetic diffusion barrier protecting efficiently the glass surface. (C) 2006 Elsevier B.V. All rights reserved.