Properties of the crossover from nonclassical to classical chemical kinetics in a reversible A+B<-->C reaction diffusion process
Abstract
We study the properties of the reaction front formed in a reversible reaction diffusion process A+B<-->C, with initially separated reactants. The case of the mobile C component is considered. In accordance with Chopard et al. [Phys. Rev. E 47, R40 (1993)] the dynamics of the front is described as a crossover between the ``irreversible'' regime at short times and the ``reversible'' regime at long times. A refined definition for the rate of C production is suggested, taking into account both the forward and the backward reaction rates. By this definition within the framework of the mean-field equations it is shown that the reversible regime is characterized by scaling of the local rate of C production as Rlocal~t-1 and by scaling of the global rate of C production as Rglobal~t-1/2. It is also established that in the considered special case of equal diffusion coefficients and equal initial concentrations, the macroscopic properties of the reaction front, such as the global rate of the C production Rglobal and the concentration profiles of the components outside the front reaction, are unchanged through this crossover.
- Publication:
-
Physical Review E
- Pub Date:
- December 1999
- DOI:
- 10.1103/PhysRevE.60.R6259
- Bibcode:
- 1999PhRvE..60.6259S
- Keywords:
-
- 82.20.Wt;
- 82.20.Mj;
- 05.40.-a;
- Computational modeling;
- simulation;
- Fluctuation phenomena random processes noise and Brownian motion