The mechanism behind the movement of charged particles in a colloidal system under the influence of an electric field is called electrophoresis. Electrophoresis is one of the electrokinetic phenomena, which involve the motion of charged particles in a dispersion medium under the influence of an electric field. Other electrokinetic phenomena include electroosmosis, streaming potential, and sedimentation potential.In electrophoresis, the charged particles in a colloidal system move due to the interaction between their surface charge and the electric field applied. The surface charge of the particles can be either positive or negative, depending on the nature of the particle and the medium. When an electric field is applied, the charged particles will migrate towards the electrode with the opposite charge. The velocity of the particles depends on factors such as the magnitude of the electric field, the size and shape of the particles, the viscosity of the medium, and the zeta potential the potential difference at the slipping plane around the particle .Knowledge of electrokinetic phenomena can be used to control the behavior and stability of colloidal suspensions in several ways:1. Particle manipulation: By applying an electric field, we can control the movement of charged particles in a colloidal suspension. This can be useful in various applications, such as separating particles based on their size, shape, or charge, or concentrating particles in a specific region.2. Stability control: The stability of a colloidal suspension is influenced by the balance between attractive and repulsive forces between the particles. Electrostatic repulsion due to the surface charge of the particles plays a significant role in maintaining stability. By controlling the surface charge e.g., through pH adjustment or addition of electrolytes , we can influence the stability of the colloidal system, either promoting flocculation aggregation of particles or maintaining a stable dispersion.3. Coating and functionalization: Knowledge of electrokinetic phenomena can be used to design and control the deposition of charged particles onto surfaces or other particles. This can be useful in applications such as creating thin films, modifying the surface properties of particles, or producing core-shell particles with specific functionalities.4. Microfluidics and lab-on-a-chip devices: Electrokinetic phenomena can be employed in microfluidic systems to manipulate and transport fluids and particles at the microscale. This can be useful in applications such as sample preparation, separation, and analysis in lab-on-a-chip devices.In summary, understanding and controlling electrokinetic phenomena can provide valuable tools for manipulating and stabilizing colloidal suspensions, with applications in various fields such as materials science, chemistry, biology, and engineering.