Title

Discrete-to-continuum simulation approach to polymer chain systems: Subdiffusion, segregation, and chain folding

Document Type

Article

Publication Date

5-1-1998

Department

Physics and Astronomy

Abstract

A discrete-to-continuum approach is introduced to study the static and dynamic properties of polymer chain systems with a bead-spring chain model in two dimensions. A finitely extensible nonlinear elastic potential is used for the bond between the consecutive bends with the Lennard-Jones (LJ) potential with smaller (R-c=2(1/6)sigma=0.95) and larger (R-c=2.5 sigma=2.1) values of the upper cutoff for the nonbonding interaction among the neighboring beads. We find that chains segregate at temperature T=1.0 with R-c=2.1 and remain desegregated with R-c=0.95. At low temperature (T=0.2), chains become folded, in a ribbonlike conformation, unlike random and self-avoiding walk conformations at T=1.0. The power-law dependence of the rms displacements of the center of mass (R-c.m.) of the chains and their center node (R-cn) with time are nonuniversal, with the range of exponents nu(1) similar or equal to 0.45-0.25 and nu(2) similar or equal to 0.30-0.10, respectively. Both radius of gyration (R-g) and average bond length ([I]) decrease on increasing the range of interaction (R-c), consistent with the extended state in good solvent to collapsed state in poor solvent description of the polymer chains. Analysis of the radial distribution function supports these observations.

Publication Title

PHYSICAL REVIEW E

Volume

57

Issue

5

First Page

5802

Last Page

5810