Phase transition of lattice polymer systems

Abstract

Monte Carlo simulations of a lattice polymer system of chains of N=20 segments each, comprising a total of 21 chains on a 21×21 square lattice, are carried out in order to clarify recent controversies concerning statistical thermodynamics of lattice models of polymers. Assuming an energy ε≳0 for every right‐angle step, we find a first‐order phase transition of disordered phase to an ordered state at k_BT_c/ε≊0.93, as demonstrated by discontinuities in the internal energy (conformational order) and the orientational order parameter. Comparison of our results with the predictions of the mean‐field lattice theory of Flory and the implications of these findings on phase transitions of real polymer systems are discussed.