Effective interactions between star polymersH.-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)
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 . 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.
82.35.Lr - Physical properties of polymers.
34.20.Gj - Intermolecular and atom-molecule potentials and forces.
44.05.+e - Analytical and numerical techniques.
© EDP Sciences 2004