The theoretical evaporation resistance of an hexagonal array of monolayer molecules

The evaporation resistance of a regular hexagonal array of monolayer molecules on a water surface has been calculated using a model in which the monolayer molecules are represented by infinitesimally thick disks, and the water molecules by hard spheres. Permeation is assumed to take place through the layer of disks only when sufficiently large holes appear owing to the independent vibrations of the disks about their lattice positions. The model predicts that there should be no permeation of water through a monolayer of long-chain alcohol molecules at areas below 24.3 Å2 molecule-1, whereas experimental data show appreciable permeation at these areas. It is concluded that the model is less satisfactory than the model (1) proposed previously, in which the disks were randomly arrayed