Molecular dynamics study of mass accommodation of methanol at liquid-vapor interfaces of methanol/water binary solutions of various concentrations

Molecular dynamics (MD) scattering simulation of methanol impinging to vapor-liquid interfaces of methanol/water mixture solutions is performed for various concentrations ranging from neat water to neat methanol. The present MD simulation predicts a mass accommodation coefficient α of methanol into neat water at 0 °C of almost unity, whereas an experimental value has been reported to be 0.056. One may conceive that the discrepancy may be attributed to the actual water surface being substantially covered by adsorbed methanol, but further MD simulation with various methanol concentrations invariantly yields an α of almost unity over the entire concentration range of the solution.