Journal of Chemical Physics, Vol.105, No.15, 6304-6314, 1996
Fluctuation-Dominated A+b-)0 Kinetics Under Short-Ranged Interparticle Interactions
In the present paper we analyze the kinetics of irreversible A+B->0 reactions in situations appropriate to electrolyte solutions. We consider diffusing species which experience short-range repulsive (attractive) interactions between like (unlike) particles and we highlight the role of fluctuations in the particles’ spatial distributions. We focus mainly on one-dimensional systems and devise a many-particle description of the reaction kinetics. In terms of our analytical approach we show that at intermediate times the interplay between fluctuations and short-ranged interactions gives rise to unusual behaviors, characterized by novel dynamical exponents of the particles’ mean concentrations, For batch reactions at longer times, when the concentrations drop off significantly, the usual fluctuation-induced behavior is recovered. We also analyze systems with external, steady sources of particles and we show that in such situations the effects of the interactions become decisive at long times. Our analytical findings are in good agreement with the results of numerical simulations, which we also present.
Keywords:DIFFUSION-CONTROLLED REACTIONS;STATE CHEMICAL-KINETICS;ANNIHILATION REACTIONS;BIMOLECULAR REACTIONS;ASYMPTOTIC-BEHAVIOR;2-SPECIES ANNIHILATION;SPATIAL-ORGANIZATION;LIMITED REACTIONS;SEGREGATION;FRACTALS