COMBINED EFFECTS OF DIFFUSION AND REACTION ON THE GROWTH OR DISSOLUTION OF SPHERICAL PARTICLES

摘要

An established implicit finite difference method was extended to predict the behaviour of particles when both diffusion and interface reaction effect the kinetics of growth or dissolution. A quasi-steadystate model was also obtained. Mixed behaviour must be expected for a relatively large range of conditions, 0.01 < a(o)k / D < 10, where k is a kinetic constant, a(o) is the initial radius, and D is diffusivity. Evolution from initial mixed control to strictly diffusion controlled growth is possible for moderate a(o)k / D, but only when the particle size becomes much larger than the initial size. [References: 14]