Structure of Electrical Double Layer at Mica/KI Solution Interface

Authors

  • Hiroshi Sakuma Tokyo Institute of Technology
  • Hironori Nakao High Energy Accelerator Research Organization
  • Yuichi Yamasaki High Energy Accelerator Research Organization
  • Katsuyuki Kawamura Okayama University

DOI:

https://doi.org/10.6000/1929-5030.2012.01.01.1

Keywords:

Surface X-ray scattering, Solid–liquid interface, Electron density, Potassium iodide, Molecular dynamics

Abstract

Solid/liquid interfaces control many physical and chemical processes such as electrokinetic phenomena, dispersion of colloidal particles, heteroepitaxial growth of alkali halide, removal of toxic elements in water. The atomic distribution at solid/liquid interfaces is strongly correlated with these properties, and understanding these atomic structures is necessary in order to establish the fundamental physics and chemistry of solid/liquid interfaces. In this study, we investigated the structure of interfaces of mica with aqueous KI solution using surface x-ray scattering. The sub-angstrom-scale electron density profile of the interface is revealed as a function of the distance normal to the interface. The electron density of the KI solution oscillates to remain 10 Å away from the surfaces. The oscillations are interpreted in terms of the adsorbed hydrated K+ ions, adsorbed water molecules, and water molecules surrounding the hydrated ions. The adsorbed K+ ions are present as inner sphere complexes and the number is enough to compensate the negatively charged mica surface. No significant difference appeared between the surface x-ray scattering profiles of the KCl and KI solution interfaces, indicating that their interfacial structures are similar.

Author Biography

Hiroshi Sakuma, Tokyo Institute of Technology

Department of Earth and Planetary Sciences

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Published

2012-10-15

How to Cite

Sakuma, H., Nakao, H., Yamasaki, Y., & Kawamura, K. (2012). Structure of Electrical Double Layer at Mica/KI Solution Interface. Journal of Applied Solution Chemistry and Modeling, 1(1), 1–5. https://doi.org/10.6000/1929-5030.2012.01.01.1

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General Articles