Principle of Zeta Potential and Its Importance
Principle of Zeta Potential
Zeta Potential is used to describe the potential of nano-level colloidal particles on its slipping plane, with the unit millivolts (mV) in general. Since the slipping plane of particles is the boundary separating itself and bulk fluid, by measuring the zeta potential, one can have the distance from the surface of particle to slipping plane. This distance constitutes the thickness of the electric double layer, which is the thickness of the positive and negative layers of ions on the interface between the particles and the fluid. The thickness can be used to determine the characteristics and stability of the colloid.
Distance to DL Results The Stability of Colloid
Relationship Between Zeta Potential & Colloid Stability
Generally, the greater the zeta potential, the greater the thickness is. With a larger zeta potential, the less likely for particles to attract agglomeration, which is beneficial to the colloid, and it is easier to maintain a stable colloidal state in suspension. Conversely, colloidal solutions with low zeta potentials are more likely to condense break and flocculate. Sometimes, it is not only destroys the nature of the colloid, but cause further damage to the target.
| Zeta potential (ζ [=] mV) | Stability |
| 0 至 ±5 |
Easily agglomerate |
| ±10 至 ±30 | Slightly Stable |
| ±30 至 ±40 | Moderately Stable |
| ±40 至 ±60 | Good Stability |
| >±60 | Excellent Stability |
In some applications, unstable colloids may damage the process or products. For example, in the semiconductor CMP wet polishing process, if the particles in the slurry agglomerate, it may cause scratches and gouges on the surface of wafer. Monitor zeta potential and understanding the condition of particles are necessary quality control processes.
Measure Zeta Potential
Some new instrument technology can not only analyze the particle size, but also measure the Zeta Potential. For example BeNano 90 Zeta Particle Size & Zeta Potential Analyzer, can measure the particle size and zeta potential of particles, fibers or powder materials, obtain the particle size and zeta potential distribution information in the system. BeNano 90 Zeta is excillent for the fields of chemistry, chemical industry, biology and medicine, such as drug delivery systems, liposomes, hydrogels, microemulsions, emulsions, polymer solutions, proteins, nano-gold particles, and so on. If you need further product consultation, please Contact ACTTR Technology, we will have professions to help you.