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Solid–Liquid Interface Structure of Muscovite Mica in SrCl(2) and BaCl(2) Solutions

[Image: see text] The structure of the solid–liquid interface formed by muscovite mica in contact with two divalent ionic solutions (SrCl(2) and BaCl(2)) is determined using in situ surface X-ray diffraction using both specular and non-specular crystal truncation rods. The 0.5 monolayer of monovalen...

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Detalles Bibliográficos
Autores principales: Pintea, Stelian, de Poel, Wester, de Jong, Aryan E. F., Felici, Roberto, Vlieg, Elias
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2018
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5951606/
https://www.ncbi.nlm.nih.gov/pubmed/29565136
http://dx.doi.org/10.1021/acs.langmuir.8b00504
Descripción
Sumario:[Image: see text] The structure of the solid–liquid interface formed by muscovite mica in contact with two divalent ionic solutions (SrCl(2) and BaCl(2)) is determined using in situ surface X-ray diffraction using both specular and non-specular crystal truncation rods. The 0.5 monolayer of monovalent potassium present at the surface after cleavage is replaced by approximately 0.25 monolayer of divalent ions, closely corresponding to ideal charge compensation within the Stern layer in both cases. The adsorption site of the divalent ions is determined to be in the surface ditrigonal cavities with minor out-of-plane relaxations that are consistent with their ionic radii. The divalent ions are adsorbed in a partly hydrated state (partial solvation sphere). The liquid ordering induced by the presence of the highly ordered crystalline mica is limited to the first 8–10 Å from the topmost crystalline surface layer. These results partly agree with previous studies in terms of interface composition, but there are significant differences regarding the structural details of these interfaces.