K. Malek et Mo. Coppens, Effects of surface roughness on self- and transport diffusion in porous media in the Knudsen regime - art. no. 125505, PHYS REV L, 8712(12), 2001, pp. 5505
The effect of surface roughness on Knudsen diffusion in nanoporous media is
investigated by means of dynamic Monte Carlo simulations in three-dimensio
nal rough fractal pores. These simulations yield new insight and explain a
number of apparent inconsistencies by revealing a striking difference betwe
en the roughness dependence of transport diffusion and gradientless (self-
or tracer) diffusion. Both analytical and simulation results show a signifi
cant roughness dependence of self-diffusion in the Knudsen regime. Transpor
t diffusion, on the other hand, is roughness independent, as the fluxes do
not depend on the detailed residence time and molecular trajectories.