From Atomic Interactions to Molecular Miscibility and Philicity: Deciphering Enthalpic Driving Forces

We present a numerical analysis on the nature of the interactions that determine the philicity of a molecule based on molecular dynamics simulations. Specifically, the focus is on a binary mixture of alkanes and perfluoroalkanes representing lipophilic and fluorophilic molecules. The enthalpic factors that lead to the mixing/demixing phase behavior are subject to study, as this phase behavior constitutes the basis of the concept of philicity. A particular feature of the present study is the application of an energy decomposition scheme, which enables the elucidation of the sensitivity of effective interaction strengths between atoms of a given species to variations in the elementary parameters of the pairwise interatomic interaction potentials (in our case, Lennard-Jones potentials).