Controlling the dispersion or flocculation of colloidal suspensions through zeta potential

Many large scale industrial processes (paper production, water treatment and dewatering processes) require de-stabilization or flocculation of dispersed particulates. For other industries and products such as foods, cosmetics, paints and pharmaceuticals, the goal often to promote stabilization and enhance shelf life and consumer appeal.

There are a number of factors that influence stability in emulsions, dispersions and suspensions. For example, adsorption of ions or surface active molecules can help to promote charge stabilization through electrostatic repulsion under some conditions, but can neutralize surface charge and destabilize dispersions under different conditions. Also, depending on whether additives adsorb to the surface of the dispersed material or remain in solution they can either promote stability or instability respectively.

Understanding a product’s requirements will determine the objectives with regards to stability, which may be to clarify a solution in order to improve filterability or promote sedimentation or alternatively to prevent an emulsion from phase separating. For ionic dispersions a key factor governing stability/instability is the zeta potential which controls the degree or electrostatic repulsion between neighboring particles.

This webinar will provide an overview of zeta potential and the mechanisms governing stability and instability. Approaches for promoting long term stability and also for inducing rapid flocculation where required will be discussed using real application examples.