Work

Breakdown of Linear Dielectric Theory for the Interaction between Hydrated Ions and Graphene

Year: 2018

Type: article

Abstract: Many vital processes taking place in electrolytes, such as nanoparticle self-assembly, water purification, and the operation of aqueous supercapacitors, rely on the precise many-body interactions between surfaces and ions in water. Here we study the interaction between a hydrated ion and a charge-neutral graphene layer using atomistic molecular dynamics simulations. For small separations, the ion-graphene repulsion is of nonelectrostatic nature, and for intermediate separations, van der Waals attraction becomes important. Contrary to prevailing theory, we show that nonlinear and tensorial dielectric effects become non-negligible close to surfaces, even for monovalent ions. This breakdown of standard isotropic linear dielectric theory has important consequences for the understanding and modeling of charged objects at surfaces.

Source: The Journal of Physical Chemistry Letters

DOI: 10.1021/acs.jpclett.8b02473

Authors: Philip Loche, Cihan Ayaz, Alexander Schlaich, Douwe Jan Bonthuis, Roland R. Netz

Institutions: Freie Universität Berlin, Centre National de la Recherche Scientifique, Laboratoire Interdisciplinaire de Physique, Université Grenoble Alpes

Language: English

Topic: Electrostatics and Colloid Interactions

Subfield: Physical and Theoretical Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: green

Funder: Deutsche Forschungsgemeinschaft

Awards: G5047987924, G790261903