Effect of Hydrogen Bonds on the Dielectric Properties of Interfacial Water

Sleeba Varghese, Sridhar Kannam, Jesper Schmidt Hansen, Sarith Sathian

Research output: Contribution to journalJournal articlepeer-review

Abstract

The dielectric constant for water is reduced under confinement. Although this phenomenon is well known, the underlying physical mechanism for the reduction is still in debate. In this work, we investigate the effect of the orientation of hydrogen bonds on the dielectric properties of confined water using molecular dynamics simulations. We find a reduced rotational diffusion coefficient for water molecules close to the solid surface. The reduced rotational diffusion arises due to the hindered rotation away from the plane parallel to the channel walls. The suppressed rotation in turn affects the orientational polarization of water, leading to a low value for the dielectric constant at the interface. We attribute the constrained out-of-plane rotation to originate from a higher density of planar hydrogen bonds formed by the interfacial water molecules.
Original languageEnglish
JournalLangmuir
Volume2019
Issue number35
Pages (from-to)8159-8166
Number of pages8
ISSN0743-7463
DOIs
Publication statusPublished - 23 May 2019

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