Curvature Dependence of the Mass Accommodation Coefficient

Mass accommodation coefficient, a parameter that captures molecular transport phenomena at liquid-vapor interfaces, is essential for predicting the growth of liquid droplets during condensation processes but is difficult to obtain experimentally. Molecular simulations have been widely used to obtain accommodation coefficients for planar interfaces, but the applicability of planar accommodation coefficients to the high-curvature interfaces present in very small droplets is not clear. In this work, molecular dynamics simulations are used to compute equilibrium mass accommodation coefficients at different temperatures for small droplets of various fluids, including Lennard-Jones and Buckingham fluids, benzene, butane, methane, methanol, and water. For all fluids studied, the mass accommodation coefficient increases with droplet size to a constant limiting value and decreases with temperature. Furthermore, the accommodation coefficient curvature dependence collapses onto a universal curve when appropriately scaled.