Charge neutrality breakdown in confined aqueous electrolytes: Theory and simulation

Abstract

We study, using Density Functional theory (DFT) and Monte Carlo simulations, aqueous electrolyte solutions between charged infinite planar surfaces, in contact with a bulk salt reservoir. In agreement with recent experimental observations [Z. Luo et al., Nat. Commun. 6, 6358 (2015)], we find that the confined electrolyte lacks local charge neutrality. We show that a DFT based on a bulk-HNC expansion properly accounts for strong electrostatic correlations and allows us to accurately calculate the ionic density profiles between the charged surfaces, even for electrolytes containing trivalent counterions. The DFT allows us to explore the degree of local charge neutrality violation, as a function of plate separation and bulk electrolyte concentration, and to accurately calculate the interaction force between the charged surfaces.

Document Details

Document Type
Pub Defense Publication
Publication Date
Sep 07, 2016
Source ID
10.1063/1.4962198

Entities

People

  • Alexandre P dos Santos
  • Matheus Girotto
  • Thiago Colla
  • Yan Levin

Organizations

  • Air Force Office of Scientific Research
  • Coordenação de Aperfeicoamento de Pessoal de Nível Superior
  • Federal University of Rio Grande do Sul
  • Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul
  • National Council for Scientific and Technological Development

Tags

Fields of Study

  • Physics

Readers

  • Computational Modeling and Simulation
  • Polymer Science and Technology
  • Quantum Chemistry