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Polymer-induced entropic depletion potential.

Authors :
Xue-Zheng Cao
Merlitz, Holger
Chen-Xu Wu
Sommer, Jens-Uwe
Source :
Physical Review E: Statistical, Nonlinear & Soft Matter Physics. Oct2011, Vol. 84 Issue 4-1, p041802-1-041802-4. 4p.
Publication Year :
2011

Abstract

We study the effective interactions between nanoparticles immersed in an athermal polymer solution using Molecular dynamics. The directly measured polymer-induced depletion forces are well described with a scaling model in which the attraction between particles is caused by the depletion of concentration blobs and thus independent of the length of the polymer chains. We find strong evidence for a repulsive barrier which arises when the distance between the particles is of the order of the correlation length of the solution and which can be interpreted as a packing effect of concentration blobs. Interestingly, the scaling picture can be extended into the regime in which higher virial coefficients of the polymer solution become relevant. We derive a universal relation between the attraction force at the particle contact, f(0), and the osmotic pressure Π as f(0) ~ Π2/3, demonstrating its validity over a wide range of concentrations of the polymer solution. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
15393755
Volume :
84
Issue :
4-1
Database :
Academic Search Index
Journal :
Physical Review E: Statistical, Nonlinear & Soft Matter Physics
Publication Type :
Academic Journal
Accession number :
70272930
Full Text :
https://doi.org/10.1103/PhysRevE.84.041802