A micromechanics approach for attachment and detachment of asymmetric colloidal particles

In this study, a micromechanics interaction model has been developed for kaolinite particles, and experiments have been performed on attachment and detachment of particles in porous media columns. The experimental results are discussed and interpreted in terms of microscopic forces, in contrast to conventional computations in the colloid literature which are based on energy terms. The force calculations are done using expressions developed for the natural shape (hexagonal platelets) of the kaolinite particles without making use of unrealistic assumptions of particle sphericity. The forces considered are van der Waals forces, electrical double layer forces, hydration forces and Born repulsion. Under constant chemical conditions, the three likely modes of interaction of kaolinite platelets showed significantly different total force curves. The microscopic force analysis was found to be consistent with experimental results.