Aggregation Rate of Charged Colloidal Particles in a Shear Flow: Trajectory Analysis Using Non-linear Poisson-Boltzmann Solution

抄録

We examined aggregation rates of colloidal particles in a shear flow as a function of KCl (potassium chloride) concentration at different shear rates. The analysis was based on the trajectory analysis with non-linear Poisson-Boltzmann (PB) solution that calculates the double layer force between highly charged particles. The trajectory analysis here is performed without any adjustable parameters. The PB solution enables us to analyze the experimental data of orthokinetic aggregation of highly charged particles where linearized PB solution is not valid. It should be noted that the comparison of the calculation with the experimental data of aggregation rates in a simple shear flow in the presence of the double layer repulsion had never been attempted until we analyzed. The theoretical calculation with trajectory analysis qualitatively describes the experimental data. However, theoretical values of critical coagulation concentration (CCC) being a bending point of capture efficiencies plotted against the KCl concentration, and capture efficiencies in the presence of double layer force are not quantitatively consistent with experimental ones. These discrepancies might be caused by the additional forces and charge heterogeneity which are not included in the present calculation.