WALLIS ZETA POTENTIAL – CORDUAN
Model: Wallis
Manufacturer: Cordouan – France
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.
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
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
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
Specifications:
| Specifications | |
| Zeta potential range | -500 mV to 500 mV |
| Mobility range | 10-10 to 10-7 m2/V.s |
| Particle size (For zeta measurement) | 1 nm up to 100 µm |
| Sample concentration | 0.0001% to 10% w/% (solvent dependent) |
| Temperature control range inside the cell | 10°C to 70°C +/-0,1°C (depending on cuvette cell material) |
| Cell options | Cuvette cell with optical quality windows compatible with organic solvents |
| Sample volume | Typically 750 µL (Hellma cell – 10 mm light path) |
| Maximum sample conductivity | 300 mS/cm |
| Sample Type | Aqueous & organic solvents – pH: 1-14 (depending on cuvette cell material) |
| Signal processing | |
| Measurement technology | Laser Doppler Electrophoresis (LDE) |
| Laser source | Highly reliable 20 mW diode @635 nm coupled to automated optical attenuation system. Other wavelengths available upon request |
| Measurement angle | Single angle for Zeta potential at 17° |
| Data processing algorithm | Fast Fourier Transform |
| Resolution | Mobility = 10-10 m2/V.s or Zeta = 0,1 mV ( in water) |
| Detector | Avalanche Photodiode – APD |
| General | |
| Computer interface | USB 2.0 – Windows XP, Seven |
| Dimensions | 33 cm x 33 cm x 38 cm (HWD) |
| Weight | 16 kg |
| Power | 100-115/220-240 VAC, 50/60 Hz, 100 W max |
| System Compliance | |
| CE certification | ISO 13099-2 : 2012 – Colloidal system – methods for zeta-potential determination – Part 2 : Optical methods |
