DEM simulation of aggregation of suspended nanoparticles

摘要: Abstract A DEM-based model was developed and examined for simulation of aggregation in suspensions α-alumina nanoparticles. In the model, random Brownian diffusion externally induced dielectrophoresis (DEP) motion were considered as driving mechanisms transport particles colloidal suspension. To simulate particle interactions, non-contact surface force contact taken into account using well-known Derjaguin-Landau-Verway-Overbeek (DLVO) theory soft-sphere respectively. Specifically, used to study effects pH, solid volume fraction external AC electric field on aggregate growth which expressed terms coordination number, longest dimension, fractal dimension. The simulations carried out over a pH range 4–10, 0.02–0.4, variety fields. relatively dilute suspensions, aggregates predominantly exhibited chainlike structures, whereas at high fraction, with complex netlike structures formed. It also evident that, concentrated DEP had negligible influence conditions. effect however, found be more noticeable structure leading formation compact greater number density. break-up reattachment sub-aggregates well rearrangement nanoparticles assemblies subsequent curling loose network promoted by strong deemed responsible this structural transformation. Finally, predict size pH. predictions good agreement published experimental data, particularly around isoelectric point.