Molecular dynamics (MD) simulations of dense carbon dioxide on the amorphous dehydroxylated silica surfaces have been carried out. The adsorption potential Surfaces of the silica solids have been obtained in order to evaluate the characteristics of the amorphous surfaces. The atom density profiles, adsorption free energy profiles, surface orientation order parameters, and radial distribution functions for the CO2 molecules have been presented in order to study the effect of the amorphous surfaces on the microscopic interfacial structure properties of the CO2 molecules. The translational diffusion and orientation rotation at silica surfaces have also been investigated. It was observed that there is marked hindrance of the translational diffusion and orientation rotation Of CO2 molecules near amorphous silica surfaces. (c) 2005 Elsevier Inc. All rights reserved.