Langmuir approach in the study of interface mass transfer

A study of the mass transport of non-reactive species through an infinite planar interface of a gas–liquid phase is presented. On the basis of the Hertz–Knudsen equation and “cluster” approaches formulated by Davidovits et al. [Journal of Physical Chemistry 95 (1991) 6337], an analytical formulation of the mass-accommodation coefficient is considered. According to the work reported herein, for the case of an interfacial equilibrium, the mass-accommodation coefficient is inversely proportional to the “cluster” factor and directly proportional to the exponential factor of the difference between free energies in the bulk and interface regions. The “cluster” factor is determined as a function of the cluster sizes in the bulk and interface. Estimation of the mass-accommodation coefficient for a series of non-reactive compounds gives a good agreement with experimental data.