Dynamic percolation theory for particle diffusion in a polymer network

Tracer-diffusion of small molecules through dense systems of chain polymers is studied within an athermal lattice model, where hard-core interactions are taken into account by means of the site exclusion principle. An approximate mapping of this problem onto dynamic percolation theory is proposed. This method is shown to yield quantitative results for the tracer correlation factor of the molecules as a function of density and chain length provided the non-Poisson character of temporal renewals in the disorder configurations is properly taken into account. (C) 2002 American Institute of Physics.