Anomalous kinetics in A + B → C with initially-separated reactants

We review recent developments in the study of the diffusion reaction system of the type A + B → C in which the reactants are initially separated. We consider the case where the A and B particles are initially placed uniformly in Euclidean space at x > 0 and x < 0 respectively. We find that whereas for d ≥ 2 a single scaling exponent characterizes the width of the reaction zone, a multiscaling approach is needed to describe the one-dimensional system. We also present analytical and numerical results for the reaction rate on fractals and percolation systems.