Diffusion in Disordered Media

In this chapter we will study diffusional transport in disordered media. We can model diffusional transport either by solving the diffusion equation or by studying the time developments of random walks—both approaches produce the same results. We will use the statistical approach and study how random walkers spread with time in free space as well as on percolation clusters. We will introduce a scaling theory for the behavior of this process in both space and time—extending our previous scaling approaches and proving us with new tools and insights.