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Attractive ion-ion correlation forces and the dielectric approximation

Pegado, Luis LU ; Jönsson, Bo LU and Wennerström, Håkan LU (2016) In Advances in Colloid and Interface Science p.1-8
Abstract

We analyze the classical problem of the interaction between two charged surfaces separated by a solution containing neutralizing counter-ions. The focus is on obtaining a description where the solvent is treated explicitly rather than through a dielectric approximation as is conventionally done. We summarize the results of three papers where we have used a Stockmayer fluid model in Monte Carlo simulations. It is shown that the attractive ion-ion correlation mechanism is also operating when the solvent is described explicitly. There appears an oscillatory component to the force, but when this is accounted for, there is a semi-quantitative agreement between the continuum model and the model with explicit solvent. The properties of the... (More)

We analyze the classical problem of the interaction between two charged surfaces separated by a solution containing neutralizing counter-ions. The focus is on obtaining a description where the solvent is treated explicitly rather than through a dielectric approximation as is conventionally done. We summarize the results of three papers where we have used a Stockmayer fluid model in Monte Carlo simulations. It is shown that the attractive ion-ion correlation mechanism is also operating when the solvent is described explicitly. There appears an oscillatory component to the force, but when this is accounted for, there is a semi-quantitative agreement between the continuum model and the model with explicit solvent. The properties of the continuum model can be reached in a molecular system by making the solvent molecules much smaller than the ions. It is demonstrated that having an explicit solvent model makes the analysis of force mechanisms more delicate due to the interplay between several different microscopic contributions to the force. Finally, it is argued that the agreement between the forces calculated using the continuum and the explicit solvent models, respectively, has as its basis the circumstance that the force between the surfaces is mainly caused by long-range ion-ion interactions, for which the dielectric approximation is most adequate. This argument applies equally well to an aqueous system as to the Stockmayer fluid.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Dielectric approximation, Double layer forces, Ion-ion correlations, Molecular solvent, Monte Carlo simulations
in
Advances in Colloid and Interface Science
pages
1 - 8
publisher
Elsevier
external identifiers
  • scopus:84962328818
  • wos:000379563300001
ISSN
0001-8686
DOI
10.1016/j.cis.2016.01.004
language
English
LU publication?
yes
id
6b6b7dab-c0d0-4a2e-9793-88d4c28ba85e
date added to LUP
2016-09-21 12:18:59
date last changed
2017-01-01 08:34:37
@article{6b6b7dab-c0d0-4a2e-9793-88d4c28ba85e,
  abstract     = {<p>We analyze the classical problem of the interaction between two charged surfaces separated by a solution containing neutralizing counter-ions. The focus is on obtaining a description where the solvent is treated explicitly rather than through a dielectric approximation as is conventionally done. We summarize the results of three papers where we have used a Stockmayer fluid model in Monte Carlo simulations. It is shown that the attractive ion-ion correlation mechanism is also operating when the solvent is described explicitly. There appears an oscillatory component to the force, but when this is accounted for, there is a semi-quantitative agreement between the continuum model and the model with explicit solvent. The properties of the continuum model can be reached in a molecular system by making the solvent molecules much smaller than the ions. It is demonstrated that having an explicit solvent model makes the analysis of force mechanisms more delicate due to the interplay between several different microscopic contributions to the force. Finally, it is argued that the agreement between the forces calculated using the continuum and the explicit solvent models, respectively, has as its basis the circumstance that the force between the surfaces is mainly caused by long-range ion-ion interactions, for which the dielectric approximation is most adequate. This argument applies equally well to an aqueous system as to the Stockmayer fluid.</p>},
  author       = {Pegado, Luis and Jönsson, Bo and Wennerström, Håkan},
  issn         = {0001-8686},
  keyword      = {Dielectric approximation,Double layer forces,Ion-ion correlations,Molecular solvent,Monte Carlo simulations},
  language     = {eng},
  pages        = {1--8},
  publisher    = {Elsevier},
  series       = {Advances in Colloid and Interface Science},
  title        = {Attractive ion-ion correlation forces and the dielectric approximation},
  url          = {http://dx.doi.org/10.1016/j.cis.2016.01.004},
  year         = {2016},
}