Competition effects in diffusion-controlled bulk reactions between ions.

A numerical solution for competitive diffusion into two static charged sinks is presented and compared against an approximate analytical solution. It is shown that for an attractive Coulomb potential the correction to the total diffusive flux of ionic reactants due to diffusion interaction between sinks may be ignored for large enough values of the Onsager length and thus the reaction rate can be described by the classical Debye formula. On the other hand, for repulsive potentials the competition becomes more profound than in the case of uncharged sinks. However, this effect is of little interest because of a small value of the diffusive flux on the reaction surface.