WALLIS Zeta Potential

WALLIS^ζTM is an innovative high resolution Zeta potential analyzer purely dedicated to nanoparticle and colloidal charge characterization.

• Based on a modern version of Laser Doppler Electrophoresis (LDE) technique
• Ideal tool for studying colloidal suspension’s stability and nanoparticles’ electrophoretic properties

Key benefits

• No electro-osmosis → Artifact-free measurements
• Improved LDE technology → Efficient, reliable & simple
• High-resolution measurement → Accurate & repeatable Zeta potential analysis
• High durability electrodes → robustness & cost-effectiveness
• Designed for standard disposable and quartz cuvette → Easy-to-fill, compatible with organic solvents and high-pH suspensions
• Advanced software functionalities (Time, pH, Temperature kinetic modes, SOPs, reporteditor, etc.)
• Easy-to-use and intuitive Graphical User Interface (GUI) software

Technologies & innovations

Dip cell : simple, robust, artifact-free

• Simple and easy sample preparation ; no risk of bubble
• Robust : high durability vitreous carbon electrodes
• Artifact-free : optimized dip cell electrodes design → no electro-osmosis bias
• High resolution measurements : sampling frequency 30 times higher than competitors / significantly improving measurement resolution down to 0,1 mV

Main characteristics

• Zeta potential measurement range: -200mV to +200 mV
• High resolution measurement: better than 0.1 mV
• Dip cell with unique high durability amorphous carbon electrodes
• ZetaQ proprietary software (lien vers onglet ZetaQ)
• Compliant with ISO 13099-2 Colloidal system – methods for Zeta potential determination – Part 2

Zeta potential (ζ)

is a fundamental property of colloidal suspension related to the effective surface electrical charges of particles immersed in a solvent.

ζ measurement is very important because it gives an indication on formulation stability and electrophoretic properties of NPs. Zeta potential is measured by the well-known technique of Laser Doppler Electrophoresis.

Laser Doppler Electrophoresis principle :

An alternative electrical field/voltage is applied between two electrodes immersed deeply in the colloidal suspension; the charged particles are forced into a translation motion (electrophoresis) with a speed (ν) proportional to the applied electrical field. The electrophoretic mobility is defined by the ratio between the particle speed and the applied field amplitude.