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

• DOI: 10.1021/acs.jpclett.8b02473
• Publication Date: 2018-10-12T13:10:36Z
• Authors: Philip Loche; Cihan Ayaz; Alexander Schlaich; Douwe Jan Bonthuis; Roland R. Netz
• Keywords: Dielectric response

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