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A systematic study of interfacial properties of binary mixtures of simpleuids wascarried out by molecular dynamics (MD) simulation and density gradient theory(DGT). Theuids are described by the Lennard-Jones truncated and shifted potentialwith truncation radius of 2.5 diameters (LJTSuid). The following interfacialproperties were studied: surface tension, relative adsorption, enrichment, and interfacialthickness. A recently developed equation of state for the LJTSuid (PeTS EOS)was used as basis for the DGT. Six binary mixtures (components 1 + 2) were studiedat a constant temperature, which was chosen such that the high-boiling component1 is subcritical while the low-boiling component 2 is either subcritical or supercritical.Furthermore, a parameter ? in the combination rule for the unlike dispersiveinteraction was varied such that the resulting mixtures showed three types of behavior:high-boiling azeotrope, ideal, and low-boiling azeotrope. The parametersof the LJTS potential, including ?, were also used in the PeTS EOS without anyadjustment. Despite this simple approach, excellent agreement between the resultsof the PeTS EOS and the MD results for the phase equilibrium and the interfacialproperties is observed. Enrichment at the interface is only found for the low-boilingcomponent 2. The enrichment increases with decreasing concentration of component2 and is favored by high boiling point di?erences of the pure components 1 and 2 andpositive deviations from Raoult's law for the mixture 1 + 2.
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