ADSORPTION-KINETICS ON FRACTAL SURFACES

A model is proposed for the description of diffusion-controlled adsorp tion kinetics on fractal surfaces. This model is based on a constituti ve equation between the mass flux and the concentration gradient of th e adsorbing species expressed in terms of a Riemann-Liouville (fractio nal) operator of noninteger order nu. The order nu depends on the frac tal dimension d(f) of the adsorbent surface, nu = d(f)-d(T), d(T) bein g its topological dimension. The model is compared with Monte Carlo si mulations and with the approach proposed by Seri-Levy and Avnir and di splays a good level of agreement with Monte Carlo data over all time s cales.