Anomalous behavior of a polymer chain in supercritical solvents: A remarkable expansion of solvophobic polymer

Conformational change of a solvophobic polymer along an isotherm slightly above critical temperature of solvent is studied by using a simulation with an effective Hamiltonian of the solvated polymer chain, where solvent effects are taken into account. We observe an expansion of the solvophobic polymer in the vicinity of the critical density. The anomalous behavior can be understood only through the large fluctuation of solvent density near the critical point.