No abstract

The adsorption of N2 molecules on the basal plane of graphite was computer simulated by the canonical (CMC) and grand canonical (GCMC) ensemble Monte Carlo methods. The dependence of the average energy of adsorption on coverage obtained by the CMC method coincides with the results of independent molecular dynamics simulations. The isotherm of adsorption obtained by the GCMC method is close to the experimental data. The small deviations of the simulated isotherm from the experiment in the submonolayer region may be explained by the residual heterogeneity of the real surface of graphite. The deviation in the region of the second layer is probably due to the many-body interactions which were not properly taken into account in the computer simulations. The results for the rigid nonspherical model of Ñ2 are compared to those for a spherical model.

Experimental adsorption isotherms of nitrogen and argon at 77.4 K and carbon dioxide at 273.2 K on C60 fullerene have been obtained to characterize the surface of this material. Grand Canonical Monte Carlo computer simulations of nitrogen physisorption have been performed that reproduce the experimental isotherm. Adsorption energy distribution functions calculated from the experimental isotherms of the studied gases are compared with the results obtained from the simulations and with experimental data obtained with other materials such as polycrystalline diamond and two carbon blacks (Vulcan 3-G and Vulcan 9). From the simulations the distributions of adsorbed molecules with respect to their gas-solid energies are discussed. Microdensity profiles are employed to calculate the local adsorption isotherms. Three adsorption sites have been identified, and the isosteric heat of adsorption at zero coverage has been calculated.

No abstract