Eur. Phys. J. B 81, 291-302 (2011)
https://doi.org/10.1140/epjb/e2011-10906-7

Force-induced desorption of self-avoiding walks on Sierpinski gasket fractals

¹ Scientific Computing Laboratory, Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia
² Institute of Condensed Matter Physics, EPFL, 1015 Lausanne, Switzerland
³ University of Belgrade, Faculty of Physics, P.O. Box 44, 11001 Belgrade, Serbia

Corresponding author: ^a suki@ff.bg.ac.rs

Received: 22 November 2010
Revised: 5 March 2011
Published online: 28 March 2011

Abstract

In this work we investigate force-induced desorption of linear polymers in good solvents in non-homogeneous environment, by applying the model of self-avoiding walk on two- and three-dimensional fractal lattices, obtained as generalization of the Sierpinski gasket fractal. For each of these lattices one of its boundaries represents an adsorbing wall, whereas along one of the fractal edges, not lying in the adsorbing wall, an external force acts on the self-avoiding walk. The hierarchical nature of the lattices under study enables an exact real-space renormalization group treatment, which yields the phase diagram of polymer critical behavior. We show that for this model there is no low-temperature reentrance in the cases of two-dimensional lattices, whereas in all studied three-dimensional cases the force-temperature dependance is reentrant. We also find that in all cases the force-induced desorption transition is of first order.