Zeta potential analysis: guarantee the stability of your colloidal dispersions
Zeta potential analysis is an essential technique for assessing the stability of colloidal suspensions, emulsions and nanoparticles. By measuring the surface charge of suspended particles, this method allows for the anticipation of aggregation phenomena, optimization of product formulation and ensuring their long-term performance.
Essential in sectors such as cosmetics, food, pharmaceuticals and water treatment, this analysis helps ensure 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 electric 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, promoting particle agglomeration 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 stages of the analysis:
- Sample preparation : The dispersion is introduced into a tank containing suitable electrodes.
- Application of an electric field : A current is applied to induce the movement of charged particles.
- Electrophoretic mobility measurement : A laser detects the speed of particles as a function of the electric field.
- Calculation of zeta potential : The collected data is used according to the Smoluchowski or Henry equation to obtain an accurate value of the zeta potential.
Technical characteristics of zeta potential analysis
Zeta potential analysis is distinguished by:
- Wide measuring range : from -200 mV to +200 mV, suitable for various types of dispersions.
- Size of analyzable particles : from a few nanometers to several microns.
- Non-destructive method : allows repeated analysis without alteration of the sample.
- Speed : results obtained in a few minutes.
- Compliance with standards : Meets the requirements of ISO 13099 for zeta potential measurement methods.
What 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 efficacy of products.
Léa Géréec
Technical and scientific advisor
