Amorphous Carbons:  Surface Structure and Adsorptive Properties

Abstract

Bernal's model is employed to represent the structure of amorphous carbonaceous materials. The adsorptive properties corresponding to this model surface are tested by means of Monte Carlo computer simulations. Nitrogen, oxygen, and carbon dioxide are the adsorbates studied at different temperatures and surface coverages. Molecular cross-sectional areas are estimated from the simulations and the results compared with values in the literature. The simulated configurations of the adsorbed molecules are discussed as well as the variation with coverage of their tilt angle distributions and their density profiles as a function of distance from the surface. Integral heats of adsorption have also been evaluated and discussed.