(328f) Comparison and Experimental Validation of Aggregation Efficiency Models

Morbidelli, M. - Presenter, Institute of Chemical and Bioengineering, ETH Zurich


Aggregation kinetics of fully destabilized polystyrene latex particles in a turbulent flow was studied experimentally in a batch stirred tank. Small angle static light scattering (SASLS) was used to monitor the time evolution of two independent moments of the cluster mass distribution (CMD), namely, the mean radius of gyration and the zero angle scattered light intensity. The obtained data and data from the literature[1], five sets in total, were used to evaluate different models to describe aggregation efficiency: Adler's solid sphere model[2], Kusters's core-shell model[3], and Bäbler's permeable sphere model[4]. Aggregation was simulated using population balance equation. Results of the simulation, using different aggregation efficiency models, were compared to the experimental data. It was found that only the models that incorporate permeability were able to predict the experimental data, i. e., Kusters's and Bäbler's models. Among these, Bäbler's model was able to better represent the aggregation efficiency.

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2. Adler, P. M., Interaction of Unequal Spheres .1. Hydrodynamic Interaction - Colloidal Forces. Journal of Colloid and Interface Science 1981, 84, (2), 461-474.

3. Kusters, K. A.; Wijers, J. G.; Thoenes, D., Aggregation kinetics of small particles in agitated vessels. Chemical Engineering Science 1997, 52, (1), 107-121.

4. Bäbler, M. U.; Sefcik, J.; Morbidelli, M.; Baldyga, J., Hydrodynamic interactions and orthokinetic collisions of porous aggregates in the Stokes regime. Physics of Fluids 2006, 18, (1).