Diffusionmediated geminate reactions under excluded volume interactions
Abstract
In this paper, influence of crowding by inert particles on the geminate reaction kinetics is theoretically investigated. Time evolution equations for the survival probability of a geminate pair are derived from the master equation taking into account the correlation among all diffusing particles, and the results are compared with those obtained by Monte Carlo simulations. In general, excluded volume interactions by the inert particles slow down the diffusive motion of reactants. However, when the initial concentration of the inert particles is uniform and high, we show that additional influence of interference between reaction and correlated diffusion accelerates the transient decay of the survival probability in the diffusioncontrolled limit. We also study the escape probability for a nonuniform initial distribution of the inert particles by taking the continuous limit in space. We show that reaction yield is increased when the reaction proceeds in the presence of a positive density gradient of the inert particles which inhibits the escape of reactants. The effect can be interpreted as a cage effect.
 Publication:

Physical Review E
 Pub Date:
 January 2012
 DOI:
 10.1103/PhysRevE.85.011131
 arXiv:
 arXiv:1106.0780
 Bibcode:
 2012PhRvE..85a1131S
 Keywords:

 02.50.r;
 82.20.w;
 Probability theory stochastic processes and statistics;
 Chemical kinetics and dynamics;
 Condensed Matter  Statistical Mechanics;
 Physics  Chemical Physics
 EPrint:
 Phys. Rev. E 85, 011131(2012)