Influence of orientational ordering transition on diffusion of carbon dioxide in carbon nanopores.

Simulation studies predicted an orientational ordering transition of the molecular axis of supercritical CO[sub 2], inside individual graphite pores, with size of the order of few molecular diameters. Study of the diffusion equation over a real porous medium, showed significant influence of the transition on the adsorbate diffusivity. Measured permeability of CO[sub 2] adsorbed in a nanoporous carbon membrane, confirmed the simulation results by exhibiting unusually high permeability values in the vicinity of the transition, and elucidated the significance of the thermodynamics in the study of the kinetic properties of the adsorbed phase. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]