Issue
Europhys. Lett.
Volume 66, Number 6, June 2004
Page(s) 874 - 880
Section Interdisciplinary physics and related areas of science and technology
DOI http://dx.doi.org/10.1209/epl/i2004-10040-x
Published online 01 June 2004
Europhys. Lett., 66 (6) , pp. 874-880 (2004)
DOI: 10.1209/epl/i2004-10040-x

Effective interactions between star polymers

H.-P. Hsu and P. Grassberger

John-von-Neumann Institute for Computing, Forschungszentrum Jülich D-52425 Jülich, Germany


(Received 11 March 2004; accepted in final form 21 April 2004)

Abstract
We study numerically the effective pair potential between two star polymers with equal arm lengths and equal number f of arms. The simulations were done for the soft-core Domb-Joyce model on the simple cubic lattice, to minimize corrections to scaling and to allow for an unlimited number of arms. For the sampling, we used the pruned-enriched Rosenbluth method (PERM). We find that the potential is much less soft than claimed in previous papers, in particular for $f\gg 1$. While we verify the logarithmic divergence of V(r), with r being the distance between the two cores, predicted by Witten and Pincus, we find that the Mayer function for f>20 is hardly distinguishable from that for a Gaussian potential.

PACS
82.35.Lr - Physical properties of polymers.
34.20.Gj - Intermolecular and atom-molecule potentials and forces.
44.05.+e - Analytical and numerical techniques.

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