Zeta Potential Analysis in Product Manufacturing

Colloidal systems are used ubiquitously in modern product manufacturing for both commercial and industrial sectors. These vary in complexity depending upon the end-product application and chemical composition of the solution. Simple colloids may comprise a single dispersive in a continuous phase dispersant media. More complicated formulations may display unstable interfaces between dispersive and continuous phases, requiring the addition of stabilising or additive agents to ensure thermodynamic stability over time.

The stability and shelf-life of colloids are largely dependent on the intermolecular characteristics of these distinct phases, which can be characterised by measuring the van der Waals forces at work within the formula. It may also be necessary to measure the electrokinetic activity of a colloid, which can be determined through zeta potential analysis.

Outlining Zeta Potential Analysis

Zeta potential analysis provides a measure of colloidal stability with regards to the strength of the dispersive—dispersant interface. This is largely determined by the ionic structures that form on the surface area of particles in a liquid: the electrical double layer. The double layer is an electrical structure formed when ions in the continuous phase adsorb to the surface of dispersed, insoluble particles. By calculating the difference in charge/repulsion between this electrical barrier and the particle, it is possible to measure the electrokinetic potential of the colloid and accurately forecast its long-term thermodynamic stability.

The performance of zeta potential analysis has shown a generally linear relationship between superior colloidal stability and high positive or negative charges. This provides actionable data for a range of processing environments including: the screening of raw construction materials; the manipulation of aggregating phenomena, such as mineral flotation; and the manufacturing of countless products.

Zeta potential analysis in product manufacturing encompasses a range of measuring techniques and colloidal systems. Microelectrophoresis is the conventional technique used to measure the electrokinetic activity of formulations, but this often requires samples to be diluted which can lead to measurement inaccuracies. Dynamic light scattering zeta potential analysis has eclipsed this traditional method, providing more reliable and rapid results for colloidal characterisation.

This has presented myriad benefits for research and development into colloids for a broad range of products and applications. These include, but are by no means limited to:

• Food and beverages: the applications of zeta potential analysis in the food and beverage sector are myriad. Dynamic light scattering can be used to determine the shelf-life of perishable goods, to assess the performance of products developed with alternative recipes, and to encourage desirable instability phenomena such as the fining of wine.
• Pharmaceuticals: dynamic zeta potential analysis is a highly-effective method of determining the stability of complex therapeutic colloids, from dermatological creams to vaccines.
• Paints and pigments: the dispersibility of nanoparticles in paints and pigments influences numerous end-product properties, including colour, texture, and application efficiency. Measuring the electrokinetic potential of commercial paints is important to ensure that particles do not undergo irreversible instability mechanics within commercially-expected shelf lives.

Zeta Potential Analysis with Meritics

Meritics supplies an extensive range of particle analysers based on the most advanced technology on the market. Our catalogue represents the cutting-edge of materials characterisation on the micro- and sub-microscales, with numerous novel techniques to support the dynamic characterisation of material behaviours.

For zeta potential analysis, we supply the DelsaMax Pro; a powerful particle size analyser that can measure the electrokinetic activity of samples as small as 45 microliters (μL) in a single second. If you would like more information about this innovative instrument, read our previous blog post: Performing Zeta Potential Measurement.

Or, contact us directly with any questions.