Zeta potential analysis: ensure the stability of your colloidal dispersions
Zeta potential analysis is an essential technique for evaluating the stability of colloidal suspensions, emulsions, and nanoparticles. By measuring the surface charge of suspended particles, this method makes it possible to anticipate aggregation phenomena, optimize product formulation, and ensure long-term performance.
Indispensable in sectors such as cosmetics, food processing, pharmaceuticals and water treatment, this analysis helps to guarantee the quality and effectiveness of formulations by preventing sedimentation and phase separation.
How does zeta potential analysis work?
Zeta potential , also called electrokinetic potential, refers to the electrical charge present at the interface between a particle and the liquid in which it is dispersed. It plays a key role in the stability of colloidal formulations.
- A high zeta potential (positive or negative) indicates strong electrostatic repulsion between particles, preventing their aggregation and maintaining stable dispersion.
- A zeta potential close to zero indicates weak repulsion, favoring the agglomeration of particles and potentially causing sedimentation or phase separation.
Zeta potential analysis is performed by laser Doppler electrophoresis , a fast and accurate method for determining the electrophoretic mobility of charged particles under the influence of an electric field.
The steps of the analysis:
- Sample preparation : The dispersion is introduced into a cuvette containing suitable electrodes.
- Application of an electric field : A current is applied to induce the movement of charged particles.
- Measurement of electrophoretic mobility : A laser detects the speed of particles as a function of the electric field.
- Calculation of the zeta potential : The data collected are used according to the Smoluchowski or Henry equation to obtain a precise value of the zeta potential.
Technical characteristics of zeta potential analysis
Zeta potential analysis is distinguished by:
- Wide measurement range : from -200 mV to +200 mV, suitable for various types of dispersion.
- Size of analyzable particles : from a few nanometers to several microns.
- Non-destructive method : allows repeated analysis without altering the sample.
- Speed : results obtained in minutes.
- Compliance with standards : meets the requirements of ISO 13099 relating to methods for measuring zeta potential.
Which matrices can be analyzed by zeta potential analysis?
Zeta potential analysis is suitable for a wide range of matrices and samples, including:
Industrial applications of zeta potential analysis
Zeta potential analysis is a key technique for many industrial sectors, where the stability of formulations directly influences the quality and effectiveness of products.
Léa Géréec
Technical and scientific expert
