title: Microscopic structure and properties of discrete water layer in Na-exchanged montmorillonite.
abstract: In this work, we focus on the atomic structure of the water interlayer of Na-exchanged montmorillonite. For two different surface charge densities, namely -0.086 and -0.172 C/m(2), the adsorption process in the presence of water is described by first principles calculations. We describe the interactions and forces for every water molecule entering the interlayer during the swelling process. In particular, the dielectric permittivity of the water interlayer is calculated. Finally, we confirm our results performing ab initio thermodynamics calculations leading to a wide range of realistic experimental scenarios.
authors.affiliation: Karlsruher Institut für Technologie, Institut für Funktionelle Grenzflächen, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; Karlsruher Institut für Technologie, Kompetenzzentrum für Materialfeuchte, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Emmerich
authors.affiliation: Karlsruher Institut für Technologie, Institut für Funktionelle Grenzflächen, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; Karlsruher Institut für Technologie, Kompetenzzentrum für Materialfeuchte, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Franz
authors.initials: F
authors.lastname: Koeniger
authors.affiliation: Karlsruher Institut für Technologie, Institut für Funktionelle Grenzflächen, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; Karlsruher Institut für Technologie, Kompetenzzentrum für Materialfeuchte, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Heike
authors.initials: H
authors.lastname: Kaden
authors.affiliation: Karlsruher Institut für Technologie, Institut für Funktionelle Grenzflächen, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany. Electronic address: peter.thissen@kit.edu.
authors.forename: Peter
authors.initials: P
authors.lastname: Thissen
keywords: Clay; Hydration; Permittivity; Swelling