Av. Barzykin et M. Tachiya, EFFECTIVE POTENTIAL APPROXIMATION TO REACTION-DIFFUSION KINETICS IN NONHOMOGENEOUS MEDIA - MICELLAR SYSTEMS, The Journal of chemical physics, 99(10), 1993, pp. 7762-7767
An approximation is introduced that enables one to describe nonhomogen
eous reaction-diffusion kinetics via a one-dimensional backward equati
on for the survival probability of a pair of particles interacting wit
h each other through the effective potential associated with the equil
ibrium distance distribution in the absence of reaction. Employing the
effective potential and mean reaction time approximations, the kineti
cs of diffusion-controlled reactions in a finite volume are analyzed,
a spherical micelle being taken as a typical example of the system. A
general relationship between the pseudo-first-order rate constant and
the spatial arrangement of reactants is obtained. Several spatial dist
ributions of practical importance are considered and the corresponding
rate constants are calculated and compared against the existing exact
analytical solutions and the results of numerical random-walk simulat
ions.