Liquid-state theory of the density dependent conformation of nonpolar linear polymers.

We use the two solvation potentials discussed in the previous paper and polymer reference interaction-site model (PRISM) theory to calculate the mutually consistent single-molecule conformation and liquid structure of model linear flexible nonpolar polymers. We focus on the mean end-to-end distance R2 and radius of gyration Rg of the single chain as functions of polymer density. Our calculations are compared to computer simulations to assess their accuracy, and some aspects of the general trends with density predicted are discussed. Two methods of calculating the conformation of the single chain in the solvation potential are used, one is Monte Carlo simulation, the other, introduced in this paper, employs a generating functional. We cannot unambiguously confirm the accuracy of one solvation potential over the other; at low density they give identical results, and the exact values are too few at high density. However, we are inclined to question the accuracy of the hypernetted-chain (HNC) style potential at high densities because it seems to predict a strong contraction of the polymer chain that is not seen experimentally in real polymer melts. [ABSTRACT FROM AUTHOR]