A molecular simulation study on solvation free energy and structural properties of polycyclic aromatic hydrocarbons in supercritical water environment

Molecular simulations have been successfully applied for studying the kinetic properties of supercritical fluids, extremely in exploring the microscopic mechanisms of high-pressure and high-temperature fluids. Molecular simulation is an efficient and convenient way to investigate complex molecular systems with supercritical water. Polycyclic aromatic hydrocarbons (PAHs) are typical coal chemical pollutants. Molecular simulations using PAH model compounds were carried out to explore the effects of supercritical water on solvation free energies and structural properties. The water density was ranging from 0.1 g/cm³ to 0.3 g/cm³ and temperature was increased from 380 °C to 440 °C. In terms of PAHs in this study, the simulations and calculations revealed that the solvation free energy remained negative and simultaneously varied with water density and temperature. This work is expected to provide a theoretical support for understanding the dynamic, structural properties and the solvation properties of different aromatic hydrocarbons in supercritical water environment.