Molecular dynamics study of a single polymer chain in solution

Abstract

We have carried out a computer simulation of the dynamics of a model polymer chain in solution. The polymer is represented by a nonamer linked through bonds which are constrained to be fixed (bead–rod model). All particles are assumed to interact via a Lennard-Jones potential and the simulations have been performed at a temperature and density which corresponds to the triple point of L-J fluids. Equilibrium properties of the chain such as end to end distance, radius of gyration, structure function, and polymer asphericity are computed. The effect of the attractive term in the L-J potential on the end to end distance and radius of gyration is discussed. The self-diffusion coefficient and time-dependent autocorrelation functions of various dynamical variables have also been calculated. All these results have been compared with those obtained for an isolated chain and wherever possible the effect of the solvent on the chain structure is commented. A qualitative comparison of present results with those of other authors is also made.