Biblioteca de la Universidad Complutense de Madrid

A combined in situ AFM and SEM study of the interaction between celestite (001) surfaces and carbonate-bearing aqueous solutions

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Sánchez Pastor, Nuria y Pina Martínez, Carlos Manuel y Fernández Díaz, Lourdes (2007) A combined in situ AFM and SEM study of the interaction between celestite (001) surfaces and carbonate-bearing aqueous solutions. Surface science, 601 . pp. 2973-2982. ISSN 0039-6028

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Resumen

In this paper, we present in situ atomic force microscopy (AFM) observations of the interaction between celestite (SrSO4) (001) surfaces and Na2CO3 aqueous solutions. The observations indicate that the interaction is characterized by a rapid alteration (carbonatation) and dissolution of the original surface, shortly followed by the formation of a new phase. EDX analyses indicate that the new phase is strontianite (SrCO3). Its crystallization involves the formation and spreading of islands of about 2.75 nm in height, which chiefly occurs on the step edges of the dissolving celestite substrate. The thickness of the islands remains almost constant during their spreading, which occurs mainly parallel to the celestite [010] direction. As a result of the progressive coalescence of the islands, a fairly homogeneous epitaxial layer forms on the celestite (001) face. At the initial stages, the formation of islands on the celestite (001) faces enhances dissolution, indicating the existence of a coupling between dissolution and crystallization reactions. Our measurements on series of FM images provided quantitative information about coupled dissolution-growth rates on a nanoscale. The effect of the coupled reactions on the celestite (001) surface on a microscopic scale was also studied by scanning electron microscopy (SEM).


Tipo de documento:Artículo
Palabras clave:Dissolution–crystallization; Celestite; Strontianite; Atomic force microscopy; Scanning electron microscopy
Materias:Ciencias > Geología > Mineralogía
Código ID:13934
Depositado:02 Dic 2011 10:55
Última Modificación:24 Sep 2015 06:11

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