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Depletion interaction between spheres in an ideal equilibrium polymer fluid: Exact asymptotic results

Woodward, Clifford E. and Forsman, Jan LU (2010) In Journal of Chemical Physics 133(15).
Abstract
We use a continuum chain model and develop an analytical theory for the interaction between two spheres immersed in a fluid of ideal equilibrium polymers. The theory can be applied to both adsorbing and nonadsorbing spheres. Here we focus on two nonadsorbing spheres and determine the classical depletion interaction between them. Compact, and exact, results are derived for the asymptotic behavior of the depletion interaction, which has a Yukawa form. We show also that in the limit of large spheres (and large surface to surface separation) the Derjaguin approximation is valid. We compare our asymptotic expression with numerical solutions of an ideal equilibrium polymer fluid consisting of discrete chains. Our asymptotic approximation... (More)
We use a continuum chain model and develop an analytical theory for the interaction between two spheres immersed in a fluid of ideal equilibrium polymers. The theory can be applied to both adsorbing and nonadsorbing spheres. Here we focus on two nonadsorbing spheres and determine the classical depletion interaction between them. Compact, and exact, results are derived for the asymptotic behavior of the depletion interaction, which has a Yukawa form. We show also that in the limit of large spheres (and large surface to surface separation) the Derjaguin approximation is valid. We compare our asymptotic expression with numerical solutions of an ideal equilibrium polymer fluid consisting of discrete chains. Our asymptotic approximation accurately predicts long-range interactions between small spheres. For large spheres it predicts the interaction very well over most of the separation range. We also consider a single sphere immersed in the polymer fluid and show how our results can be generalized to treat polydisperse polymer fluids, where the polydispersity is described by a Schulz-Flory distribution. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3494037] (Less)
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organization
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type
Contribution to journal
publication status
published
subject
in
Journal of Chemical Physics
volume
133
issue
15
publisher
American Institute of Physics
external identifiers
  • wos:000283359300063
  • scopus:78049231898
ISSN
0021-9606
DOI
10.1063/1.3494037
language
English
LU publication?
yes
id
05597c4c-c4b9-40fc-9880-553a370a3dee (old id 1720441)
date added to LUP
2010-12-09 13:23:17
date last changed
2018-05-29 09:45:48
@article{05597c4c-c4b9-40fc-9880-553a370a3dee,
  abstract     = {We use a continuum chain model and develop an analytical theory for the interaction between two spheres immersed in a fluid of ideal equilibrium polymers. The theory can be applied to both adsorbing and nonadsorbing spheres. Here we focus on two nonadsorbing spheres and determine the classical depletion interaction between them. Compact, and exact, results are derived for the asymptotic behavior of the depletion interaction, which has a Yukawa form. We show also that in the limit of large spheres (and large surface to surface separation) the Derjaguin approximation is valid. We compare our asymptotic expression with numerical solutions of an ideal equilibrium polymer fluid consisting of discrete chains. Our asymptotic approximation accurately predicts long-range interactions between small spheres. For large spheres it predicts the interaction very well over most of the separation range. We also consider a single sphere immersed in the polymer fluid and show how our results can be generalized to treat polydisperse polymer fluids, where the polydispersity is described by a Schulz-Flory distribution. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3494037]},
  articleno    = {154902},
  author       = {Woodward, Clifford E. and Forsman, Jan},
  issn         = {0021-9606},
  language     = {eng},
  number       = {15},
  publisher    = {American Institute of Physics},
  series       = {Journal of Chemical Physics},
  title        = {Depletion interaction between spheres in an ideal equilibrium polymer fluid: Exact asymptotic results},
  url          = {http://dx.doi.org/10.1063/1.3494037},
  volume       = {133},
  year         = {2010},
}