What is the significance of zeta potential measurement? How to measure?

The surface potential of particles cannot usually be measured, but the zeta potential can be measured directly. Generally, the thicker the electric double layer, the Zeta

The higher the potential, the absolute value of the Zeta point plays a role here, regardless of the sign of positive or negative electricity.

The existence of the double electric layer is an important factor in the stability of the dispersion system. When charged particles approach each other in the solution, the double electric layer around the particles is cross-linked, resulting in electrostatic repulsion, thereby preventing the particles from getting closer and avoiding agglomeration. . A very important principle in the selection of dispersant or surface modifier is that it must match the electrical properties of the particle surface. If the particle surface is positively charged, the dispersant should be negatively charged. Zeta potential measurement usually uses the electrophoresis method. Charged particles move under the action of an electric field, and their movement speed (called electrophoresis speed) is directly proportional to the Zeta potential. Theoretically it can be calculated.

The simplest way to measure Zeta potential is to directly observe the electrophoretic movement of particles with a microscope. The charged sign of the particles can be judged according to the direction of movement of the particles. The Zeta potential can be calculated from the movement speed of the particles and the size of the electric field.