Random sequential adsorption of polyatomic species on fractal substrates

Random sequential adsorption of k-mers of different sizes and shapes deposited on two types of fractal surfaces (deterministic and statistical) is studied. These kinds of substrates present intrinsic heterogeneities. As a consequence, the average coordination number depends on the topology that characterizes the adsorbent. For discrete models, at the late stage the surface coverage evolves according to θ(t)=θ(j)-Aexp[-t/σ], where θ(j) is the jamming coverage while A and σ are fitting parameters. A detailed analysis of how these main quantities [θ(j), σ] depend on the relationship between the geometry of the adsorbate and the adsorbent is presented. The results obtained suggest that the symmetry of the substrate may exert a decisive influence on the adsorption kinetics of polyatomic species.