Abstract
A modified Smoluchowski theory in which the hydrodynamic interaction and Van der Waals-London potential between particles are taken into account is proposed for the rapid Brownian coagulation of colloidal dispersions and compared with experiments on coagulations of polystyrene latex particles in KC1 solutions. It is found that the theory is physically consistent with experiments and predicts the time-dependent behavior of particles for a sufficiently long time with considerable accuracy. The existence of an asymptotic particle-size distribution, the self-preserving distribution, is confirmed by experiments. These results indicate that the theory is applicable to the floe formation process where large and irregular particles are dominant, as well as to the initial stage of coagulation.