The Electrokinetic Connection
Understanding zeta potential can help you to understand and control colloidal suspensions. Examples include complex biological systems such as blood and functional ones like paint. Water, milk, wine, clay, inks, dyes, paper, and pharmaceuticals are good examples of useful colloidal systems. In many cases, the performance of a suspension can be improved by understanding the effects of colloidal behavior on such properties as viscosity, settling, and effective particle size.

Each colloid carries a "like" electrical charge which produces a force of mutual electrostatic repulsion between adjacent particles. If the charge is high enough, the colloids will remain discrete, dispersed, and in suspension. Reducing or eliminating the charge has the opposite effect- the colloids will steadily agglomerate and settle out of suspension or form an interconnected matrix.

We can often tailor the characteristics of a suspension by understanding how individual colloids interact with one another. At times we may want to maximize the repulsive forces between them in order to keep each particle discrete and prevent them from gathering into larger, faster settling agglomerates. Examples include pharmaceuticals and pastes. Sometimes we have the opposite goal and want to separate the colloid from the liquid. Removing the repulsive forces allows them to form large flocs that settle fast and filter easily. Viscosity is another property that can be modified by varying the balance between repulsion and attraction.

Each charged particle is surrounded by a diffuse layer of neutralizing ions. This causes an electrical potential on the order of millivolts to develop across the diffuse layer between the colloid and the bulk of the liquid. The magnitude of this potential is approximately proportional to the surface charge on the colloid, and it is called the zeta potential.

 

Products

 

ZetaCAD

Applicable to particles above 50um diameter and flat surfaces. Reliable and easy to set up , Menu driven Windows Software. Measurement and system rinse are fully automated.

ZetaCompact

Modular system for measuring Electrolytic mobility from 50nm to 50um and calculating the zeta potential of colloid solutions

 

ZetaPhoremeter IV

Designed to provide a modular tool for measuring the Zeta potential and electrophoretic mobility of Coloid solutions

 

 

Contact Us to discuss service contracts, overhauls, on-site support, parts and consumables.