Patch-distribution effect on diffusion-limited process in dilute suspension of partially active spheres

摘要

The normalized overall rate constant, k(p)/k(f) for diffusion-limited processes in a dilute suspension of spheres, partially covered with active patches of varying distribution states, is studied with sped-up Brownian dynamic simulations. A dimensionless separation index I-s is defined to quantify the characteristics of patch distribution on the sphere surfaces, with values of 0 and 1 corresponding to the states of the most compact and loosest patch distributions, respectively. Remarkably, the normalized overall rate constant is found to strongly correlate with the dimensionless separation index at fixed patch coverage f(cover) exhibiting a positive, linear relationship. In addition, the slope of the k(p)/k(f) vs I-s line, a measure of sensitivity of k(p)/k(f) to variation in the separation state of the distributed patches, is found to depend on patch coverage and patch size. This sensitivity exhibits a maximum value with respect to an increase in patch coverage, and the magnitude of the maximum sensitivity decreases with increasing patch size. The patch coverage, at which the maximum sensitivity occurs, increases with increasing patch size.