Calculation of the intrinsic solvation free energy profile of methane across a liquid/liquid interface in computer simulations

The transfer of ions and neutral particles through water/organic interfaces has been widely studied in the last few decades by both experimental and theoretical methods. The reason for the never ceasing interest in this field is the importance of transport phenomena in electrochemistry, biochemistry and separation science. In the current paper the solvation Helmholtz free energy profile of a methane molecule is presented, with respect to the intrinsic (i.e., real, capillary wave corrugated) interface of water and 1,2-dichloroethane, as obtained from constrained molecular dynamics simulations. The results of the current calculation are analysed in comparison with the solvation free energy profile of the chloride ion across the same interface.