Open AccessMONTE CARLO SIMULATIONS OF THE ADSORPTION OF DIMERS ON STRUCTURED HETEROGENEOUS SURFACES
Author(s) -
Charlles R. A. Abreu,
Flávio Peixoto,
Reginaldo O. Corrêa,
A. Silva Telles,
Frederico W. Tavares
Publication year - 2001
Publication title -
brazilian journal of chemical engineering/brazilian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.313
H-Index - 52
eISSN - 1678-4383
pISSN - 0104-6632
DOI - 10.1590/s0104-66322001000400004
Subject(s) - adsorption , monte carlo method , dimer , grand canonical ensemble , chemistry , lattice (music) , molecule , chemical physics , materials science , statistical physics , computational chemistry , physics , mathematics , organic chemistry , statistics , acoustics
The effect of surface topography upon the adsorption of dimer molecules is analyzed by means of grand canonical ensemble Monte Carlo simulations. Heterogeneous surfaces were assumed to consist of a square lattice containing active sites with two different energies. These were distributed in three different configurations: a random distribution of isolated sites; a random distribution of grains with four high-energy sites; and a random distribution of grains with nine high-energy sites. For the random distribution of isolated sites, the results are in good agreement with the molecular simulations performed by Nitta et al. (1997). In general, the comparison with theoretical models shows that the Nitta et al. (1984) isotherm presents good predictions of dimer adsorption both on homogeneous and heterogeneous surfaces with sites having small differences in characteristic energies. The molecular simulation results also show that the energy topology of the solid surfaces plays an important role in the adsorption of dimers on solids with large differences in site energies. For these cases, the Nitta et al. model does not describe well the data on dimer adsorption on random heterogeneous surfaces (grains with one acid site), but does describe reasonably well the adsorption of dimers on more patchwise heterogeneous surfaces (grains with nine acid sites)