Aggregation in colloidal suspensions: Effect of colloidal forces and hydrodynamic interactions

• Published in: Advances in colloid and interface science Vol. 179-182; pp. 99 - 106
• Main Authors: Kovalchuk, N.M., Starov, V.M.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.11.2012
• Subjects: Agglomeration; Aggregation; Colloidal forces; Colloidal suspensions; Colloids; Computational fluid dynamics; Computer simulation; Fluid flow; Hydrodynamic interactions; Hydrodynamics; Kinetics; Langevin equations; Mathematical analysis; Mathematical models; Models, Theoretical; Suspensions - chemistry; Aggregation; Colloidal suspensions; Langevin equations; Hydrodynamic interactions; Colloidal forces
• ISSN: 0001-8686; 1873-3727
• DOI: 10.1016/j.cis.2011.05.009

The forces acting in colloidal suspensions and affecting their stability and aggregation kinetics are considered. The approximations used for these forces in numerical simulations and the importance of the balanced account for both colloidal forces and hydrodynamic interactions are discussed. As an example the results of direct numerical simulations of kinetics of aggregation either with account for hydrodynamic interaction between particles or without it are compared by varying the parameters of the interaction potential between particles and fraction of solid. Simulations are based on the Langevin equations with pairwise interaction between particles and take into account Brownian, hydrodynamic and colloidal forces. It is confirmed that the neglecting of hydrodynamic interaction results in an accelerated growth of aggregates. The results of numerical simulations of aggregation kinetics are compared with well known analytical solutions. Aggregates formed at the fraction of solid 0.32; time of aggregation 20s; depths of the potential well Umin=6kT. [Display omitted] ► Forces affecting stability and aggregation kinetics of colloidal suspensions. > Brownian dynamic simulations of aggregation kinetics. ► Reversible aggregation with constant average size of aggregates at 4-8 kT. ► Aggregates growth rate is overestimated by neglecting of hydrodynamic interactions.