Deposition of Brownian particles in the presence of energy barriers of DLVO theory: effect of the dimensionless groups

The problem of deposition of colloidal particles onto a collector surface i s investigated theoretically using Brownian dynamics simulations. Using the Kuwabara model for the flow field around the collector surface, we examine the effects of the total interaction energy profiles of the DLVO theory on the collection efficiencies. The simulation results show that: (1) the Bro wnian diffusion effect of particles becomes pronounced when the value of Re ynolds number is close to the laminar flow region, (2) a particle size with a minimum collection efficiency exists, and (3) the dimensionless groups, N-L0, N-DL, N-E1 and N-E2 which characterize the height of the primary maxi mum and the depth of the secondary minimum in the total interaction energy curve play a major role in determining the collection efficiency of Brownia n particles with low Reynolds numbers. In addition, we compare the present theoretical results with the;available experimental data [FitzPatrick J. A. and Spielman L. A. (1973) J. Colloid Interface Sci. 43, 350-369], and find that the simulation results obtained from the present model coincide more closely with the experimental data than those results obtained from the cas e where the Brownain diffusion effect is neglected. (C) 1998 Elsevier Scien ce Ltd. All rights reserved.