title: Effects of surface roughness on self- and transport diffusion in porous media in the Knudsen regime.
abstract: The effect of surface roughness on Knudsen diffusion in nanoporous media is investigated by means of dynamic Monte Carlo simulations in three-dimensional rough fractal pores. These simulations yield new insight and explain a number of apparent inconsistencies by revealing a striking difference between the roughness dependence of transport diffusion and gradientless (self- or tracer) diffusion. Both analytical and simulation results show a significant roughness dependence of self-diffusion in the Knudsen regime. Transport diffusion, on the other hand, is roughness independent, as the fluxes do not depend on the detailed residence time and molecular trajectories.
authors.affiliation: Delft Department of Chemical Technology, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands.
authors.forename: K
authors.initials: K
authors.lastname: Malek
authors.forename: M O
authors.initials: MO
authors.lastname: Coppens