Concentration Profiles and Reaction Fronts in A + B -> C Type Processes: Effect of Background Ions

Abstract

Diffusion and reaction of initially separated ions A- and B+ in the presence of counter ions A'+ and B'- is studied. The dynamics is described in terms of reaction-diffusion equations obeying local electroneutrality, and the time-evolution of ion-concentrations is determined. We find that, in the absence of reactions, unequal mobility of ions generate nontrivial features in the macroscopically observable concentration profiles. Switching on the reaction (A-) + (B+) -> C leads to the formation of a localized, diffusive reaction front and one finds that the properties of the front (e.g. effective diffusion constant) are affected by the background ions. The consequences of this effect on the formation of Liesegang patterns is discussed.

7 pages, 8 ps figures

References in corpus (3)

• Derivation of the Matalon-Packter law for Liesegang patterns
• Formation of Liesegang patterns: A spinodal decomposition scenario
• Formation of Liesegang Patterns

Cited by in corpus (6)

• Designer Patterns: Flexible Control of Precipitation through Electric Currents
• Formation of Liesegang patterns: Simulations using a kinetic Ising model
• Formation of Liesegang patterns in the presence of an electric field
• Diffusion-controlled annihilation $A+B\to 0$ with initially separated reactants: The death of an $A$ particle island in the $B$ particle sea
• Front motion in an $A+B\to C$ type reaction-diffusion process: Effects of an electric field
• Width of reaction zones in A + B -> C type reaction-diffusion processes: Effects of an electric current