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Limitations of the Derjaguin approximation and the Lorentz-Berthelot mixing rule.

Forsman, Jan LU and Woodward, Clifford E (2010) In Langmuir 26(7). p.4555-4558
Abstract
We investigate the Derjaguin approximation by explicitly determining the interactions between two spherical colloids using density functional theory solved in cylindrical coordinates. The colloids are composed of close-packed Lennard-Jones particles. The solvent particles are also modeled via Lennard-Jones interactions. Cross interactions are assumed to follow the commonly used Lorentz-Berthelot (LB) mixing rule. We demonstrate that this system may display a net repulsive interaction across a substantial separation range. This contradicts the Hamaker-Lifshitz theory, which predicts attractions between identical polarizable particles immersed in a polarizable medium. The source of this repulsion is traced to the LB mixing rule.... (More)
We investigate the Derjaguin approximation by explicitly determining the interactions between two spherical colloids using density functional theory solved in cylindrical coordinates. The colloids are composed of close-packed Lennard-Jones particles. The solvent particles are also modeled via Lennard-Jones interactions. Cross interactions are assumed to follow the commonly used Lorentz-Berthelot (LB) mixing rule. We demonstrate that this system may display a net repulsive interaction across a substantial separation range. This contradicts the Hamaker-Lifshitz theory, which predicts attractions between identical polarizable particles immersed in a polarizable medium. The source of this repulsion is traced to the LB mixing rule. Surprisingly, we also observe nonmonotonic convergences to the Derjaguin limit. This behavior is best understood by decomposing the total interaction between the colloids into separate contributions. With increasing colloid size, each of these contributions approach the Derjaguin limit in a monotonic manner, but their different rates of convergence mean that their sum may display nonmonotonic behavior. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Langmuir
volume
26
issue
7
pages
4555 - 4558
publisher
The American Chemical Society
external identifiers
  • wos:000275995100001
  • pmid:20180569
  • scopus:77950568116
ISSN
0743-7463
DOI
10.1021/la904769x
language
English
LU publication?
yes
id
ac42efd6-6d84-4192-b3db-ca4af9506c38 (old id 1582962)
date added to LUP
2010-05-20 10:26:23
date last changed
2018-05-29 10:48:03
@article{ac42efd6-6d84-4192-b3db-ca4af9506c38,
  abstract     = {We investigate the Derjaguin approximation by explicitly determining the interactions between two spherical colloids using density functional theory solved in cylindrical coordinates. The colloids are composed of close-packed Lennard-Jones particles. The solvent particles are also modeled via Lennard-Jones interactions. Cross interactions are assumed to follow the commonly used Lorentz-Berthelot (LB) mixing rule. We demonstrate that this system may display a net repulsive interaction across a substantial separation range. This contradicts the Hamaker-Lifshitz theory, which predicts attractions between identical polarizable particles immersed in a polarizable medium. The source of this repulsion is traced to the LB mixing rule. Surprisingly, we also observe nonmonotonic convergences to the Derjaguin limit. This behavior is best understood by decomposing the total interaction between the colloids into separate contributions. With increasing colloid size, each of these contributions approach the Derjaguin limit in a monotonic manner, but their different rates of convergence mean that their sum may display nonmonotonic behavior.},
  author       = {Forsman, Jan and Woodward, Clifford E},
  issn         = {0743-7463},
  language     = {eng},
  number       = {7},
  pages        = {4555--4558},
  publisher    = {The American Chemical Society},
  series       = {Langmuir},
  title        = {Limitations of the Derjaguin approximation and the Lorentz-Berthelot mixing rule.},
  url          = {http://dx.doi.org/10.1021/la904769x},
  volume       = {26},
  year         = {2010},
}