Electrostatic Relaxation and Hydrodynamic Interactions for Self-Diffusion of Ions in Electrolyte Solutions

Dufreche, JF and Jardat, M and Turq, P and Bagchi, B (2008) Electrostatic Relaxation and Hydrodynamic Interactions for Self-Diffusion of Ions in Electrolyte Solutions. In: Journal of Physical Chemistry B, 112 (33). pp. 10264-10271.

PDF full.pdf - Published Version Restricted to Registered users only Download (143kB) | Request a copy

Abstract

The concentration dependence of self-diffusion of ions in solutions at large concentrations has remained an interesting yet unsolved problem. Here we develop a self-consistent microscopic approach based on the ideas of mode-coupling theory. It allows us to calculate both contributions which influence the friction of a moving ion: the ion atmosphere relaxation and hydrodynamic interactions. The resulting theory provides an excellent agreement with known experimental results over a wide concentration range. Interestingly, the mode-coupling self-consistent calculation of friction reveal a nonlinear coupling between the hydrodynamic interactions and the ion atmosphere relaxation which enhances ion diffusion by reducing friction, particularly at intermediate ion concentrations. This rather striking result has its origin in the similar time scales of the relaxation of the ion atmosphere relaxation and the hydrodynamic term, which are essentially given by the Debye relaxation time. The results are also in agreement with computer simulations, with and without hydrodynamic interactions.

Item Type:	Journal Article
Publication:	Journal of Physical Chemistry B
Publisher:	American Chemical Society
Additional Information:	Copyright of this article belongs to American Chemical Society.
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	12 Sep 2008 05:02
Last Modified:	19 Sep 2010 04:49
URI:	http://eprints.iisc.ac.in/id/eprint/15731

Actions (login required)

View Item