Contribution to the variation with coverage of the isosteric heat of adsorption on a square lattice and in incompletely separated cells
Abstract
A Monte Carlo evaluation is made of a model for adsorption on a two-dimensional square lattice. This model corresponds to one which has been previously suggested for sorption in zeolites and which was successful in predicting maxima in graphs of the isosteric heat against coverage whilst invoking repulsive rather than attractive interactions between the sorbed molecules. For the present model the maxima are found near half-saturation of the best sites, as compared with near-full saturation for the zeolite model. A further model, intermediate in character between the previous two and for which an analytic solution by statistical mechanics is possible, was found to show maxima at values of the coverage which were closer to those for the infinite two-dimensional model than for the zeolite model.