Molecular dynamics simulation of polycyclic aromatic hydrocarbons solvation behavior in supercritical carbon dioxide under different pressure and temperature

In this work, the solvation behavior of polycyclic aromatic hydrocarbons (PAHs) in supercritical carbon dioxide (sCO₂) was investigated by molecular dynamics simulation. The effects of changing temperature and pressure on the solvation behavior were studied. In addition, the value of the interaction binding energy of PAHs-sCO₂ and the radial distribution function at various conditions was calculated to study the solvation mechanism. The simulation results showed that high pressure and low temperature can promote the solvation of PAHs in sCO₂. However, the effect of pressure change on the solvation behavior was considerably less noticeable than that of temperature change. Furthermore, the solvation of heavy PAHs appeared to be harder than light PAHs. The interaction energy between sCO₂ and PAHs decreased as temperature increased, while increased as pressure increased. Moreover, the interaction mechanism analysis found that the van der Waals interaction force dominated the interaction force between sCO₂ and PAHs molecules.