Entropic collapse transition of a polymer in a solvent with a nonadditive potential.
We use molecular dynamics simulations to study an entropy-driven collapse transition of a flexible polymer in a solvent. Monomers and solvent particles interact with a steeply repulsive soft-sphere potential. We consider a nonadditive potential system in which the effective diameter describing the solvent-monomer interaction is greater than or equal to the diameters corresponding to the solvent-solvent and monomer-monomer interactions, which are set equal. We examine the effects of nonadditivity of the solvent-monomer potential and solvent density on the collapse transition. We find that a small degree of nonadditivity will drive the transition at sufficiently high solvent density. Increasing the density leads to a collapse transition at lower values of nonadditivity.
Polson
J M
JM
Centre for the Physics of Materials, Department of Physics, McGill University, Rutherford Building, 3600 Rue Université, Montréal, PQ, Canada H3A 2T8.