Springer LINK: The European Physical Journal B - Abstract Volume 5 Issue 4 (1998) pp 899-904

The European Physical Journal B

ISSN: 1434-6028 (printed version)
ISSN: 1434-6036 (electronic version)

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Abstract Volume 5 Issue 4 (1998) pp 899-904

Tension of polymers in a strip

J.F. Stilck (1) (a), K.D. Machado (2)

(1) Instituto de Física, Universidade Federal Fluminense, A. Litorânea, s/n 24210-340, Niterói, RJ Brazil
(2) Departamento de Física Geral, Instituto de Física, Universidade de S ao Paulo, C.P. 66318 05315-970 S ao Paulo, SP Brazil

Received: 5 January 1998 / Revised: 2 June 1998 / Accepted: 4 June 1998

Abstract: We consider polymers, modelled as self-avoiding chains, confined on a strip defined on the square lattice with spacing a in the (x,y) plane, limited by two walls which are impenetrable to the chains and located at x=0 and x=am. The activity of a monomer incorporated into the chain is defined as $z=\exp(\beta\mu)$ and each monomer adsorbed on the wall, that is, located at sites with x=0 or x=m, contributes with a Boltzmann factor $\omega=\exp(-\beta\epsilon)$ to the partition function. Therefore, $\epsilon<0$ corresponds to walls which are attractive to the monomers, while for $\epsilon\gt$ the walls are repulsive. In particular, we calculate the tension between the walls, as a function of m and $\omega$, for the critical activity z_c, at which the mean number of monomers diverges (the so called polymerization transition). For $\omega \gt 1 \to 1.549375...$, the tension on the walls is repulsive for small values of m, becoming attractive as m is increased and finally becoming repulsive again. As $\omega$ is increased, the region of values of m for which the tension is attractive grows.

PACS. 05.50.+q Lattice theory and statistics; Ising problems - 61.41.+e Polymers, elastomers, and plastics

(a) On a leave from Departamento de Física, Universidade Federal de Santa Catarina. email: jstilck@if.uff.br

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