Simulation of polymers by self-avoiding, nonintersecting random chains at various concentrations

Abstract

Monte Carlo calculations have been carried out on systems of multiple excluded‐volume chains for different concentrations on various two‐ and three‐dimensional lattices. For eight‐link chains the mean square end‐to‐end separation and other dimensional parameters have been computed for concentrations up to 95% of bulk. The effect of intermolecular volume exclusion is to decrease the average chain dimensions markedly as the concentration is increased. The limiting values of the shape parameters for bulk polymer appear to correspond to the values for eight‐step random walks without step reversals (second order walks). Calculations for 20‐link chains on the triangular lattice also approach the second order limit. The radial distribution function projected onto the x axis for eight‐link walks on the square planar lattice is given for 95% concentration and is compared to the distributions for single chain second order and self‐avoiding walks. A theoretical explanation is offered to account for the approach of the average dimensions of the bulk polymer to the corresponding second order walk values.