The static properties of two-dimensional excluded volume continuum multichain systems are investigated by a "reptation" Monte Carlo algorithm. All beads interact via a repulsive (shifted) Lennard-Jones potential. In addition, nearest neighbors along chains are linked by a quasiharmonic potential which permits limited pair extensions. Chain lengths of 5, 10, 20, 32, 50, and 70 beads have been studied. Studies at densities of 0.1, 0.3, and 0.5 demonstrate that chain dimensions are compressed as the concentration is increased. Both the mean square end-to-end distance 〈R2〉, and the mean square radius of gyration 〈S2〉 have a power law dependence upon l-1, the number of bonds, with exponent approximately 1.44 for ρ = 0.1, 1.33 for ρ = 0.3, and 1.20 for ρ = 0.5. The asphericity ratios indicate the extent of compression as the density is increased. In addition, nonexcluded volume chains are studied via straightforward Monte Carlo integration. 〈R2〉 and 〈S2〉 have a power law dependence upon l-1 with exponent 1.00.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry