P. Serra et Jf. Stilck, POLYMER MODEL WITH ANNEALED DILUTION ON THE SQUARE LATTICE - A TRANSFER-MATRIX STUDY, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 49(2), 1994, pp. 1336-1343
We study a lattice model for equilibrium polymerization with annealed
dilution. The model considered is an Ising lattice-gas monomer-solvent
system where the polymers are represented by mutually and self-avoidi
ng walks constrained to pass through sites occupied by monomers. Numer
ical results on the square lattice using transfer-matrix techniques an
d finite-size scaling are reported. The values obtained for the tricit
ical exponent nu(t) are in agreement with the tricritical Ising expone
nt (8/11) for high values of the monomer fugacity, but the accuracy we
obtained does not rule out the possibility of nu(t) being equal to th
e critical self-avoiding-walk (SAW) value 3/4. Our results indicate th
at a crossover occurs in the tricritical behavior of the model. This c
rossover corroborates the equivalence between a particular limit of th
e diluted model and the self-attracting polymer system proposed recent
ly.