Hydration of Na , Ni2 , and Sm3 in the Interlayer of Hectorite: A Quasielastic Neutron Scattering StudyReportar como inadecuado




Hydration of Na , Ni2 , and Sm3 in the Interlayer of Hectorite: A Quasielastic Neutron Scattering Study - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

1 LGIT - Laboratoire de Géophysique Interne et Tectonophysique 2 ISTO - Institut des Sciences de la Terre d-Orléans 3 ILL - Institut Laue-Langevin

Abstract : Quasielastic neutron scattering experiments were performed with Na−hectorite, Ni−hectorite, and Sm−hectorite samples in order to find out whether Sm3+ is present in the clay interlayer as a fully hydrated cation outer-sphere complex, or, as it follows from neutron diffraction data analysis, it is dehydrated and bound to the clay surface inner-sphere complex. The results obtained for the Sm−hectorite were compared with other interlayer cations: strongly hydrated Ni2+ and relatively weakly hydrated Na+. It was found that water mobility in the Sm−hectorite sample is very close to the water mobility in Ni−hectorite. This is only possible if the Sm3+ ion is fully hydrated. It was shown that water molecules hydrating Ni2+ and Sm3+ exhibit diffusion mobility measurable with backscattering spectrometers. The diffusion coefficients of the exchangeable cations were found using the slow exchange approximations DNi = 0.05 − 0.14 × 10−9 m2-s and DSm = 0.04 − 0.18 × 10−9 m2-s.





Autor: Oleg S. Sobolev - Lydie Le Forestier - Miguel A. Gonzales - Laurent Charlet -

Fuente: https://hal.archives-ouvertes.fr/



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