The electrokinetic potential plays a crucial role in determining the stability of colloidal systems. One of the key parameters used to describe the electrokinetic potential of a colloidal system is the zeta potential. The zeta potential is the electric potential at the slipping plane, which is the boundary between the immobile fluid layer attached to the particle surface and the mobile fluid layer in the dispersion medium.The zeta potential affects the stability of colloidal systems in several ways:1. Particle repulsion: When the zeta potential of colloidal particles is high either positive or negative , the particles repel each other due to the presence of similar charges on their surfaces. This repulsion prevents the particles from coming together and aggregating, thus maintaining the stability of the colloidal system.2. Particle attraction: If the zeta potential is low or close to zero, the electrostatic repulsion between the particles is weak. In this case, the attractive van der Waals forces between the particles may dominate, causing the particles to come together and aggregate, leading to the destabilization of the colloidal system.3. Steric stabilization: In some cases, the stability of colloidal systems can be maintained by steric stabilization, which involves the adsorption of polymers or surfactants onto the particle surfaces. These adsorbed layers can provide a physical barrier that prevents the particles from coming into close contact and aggregating. The zeta potential can be influenced by the presence of these adsorbed layers, which can affect the overall stability of the colloidal system.4. pH and ionic strength: The zeta potential of colloidal particles can be affected by the pH and ionic strength of the dispersion medium. Changes in these parameters can alter the surface charge of the particles, which in turn can influence the electrostatic repulsion or attraction between the particles and ultimately affect the stability of the colloidal system.In summary, the electrokinetic potential, as represented by the zeta potential, plays a significant role in determining the stability of colloidal systems. A high zeta potential either positive or negative generally indicates a stable colloidal system due to strong electrostatic repulsion between particles, while a low zeta potential can lead to particle aggregation and destabilization of the system. Additionally, factors such as steric stabilization, pH, and ionic strength can also influence the zeta potential and the overall stability of colloidal systems.