WALLIS Zeta Potential
WALLISζTM 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.
WALLIS Zeta Potential
ZetaQ
A software fully-dedicated to Zeta potential measurement for WALLIS featuring :
- User-friendly and intuitive GUI
- User-defined Standard Operation Procedures (SOPs)
- Programmable kinetic experiments (Zeta vs T° / pH / time)
- Post-data processing
- Exhaustive solvent database
- Automatic report editor for results presentation and saving
- Experiments and results storage in database.
ZetaQ is designed to guide the user in a very simple and intuitive way, through the different steps of a measurement, as does NanoQ. Its access menu allows to select in one click an operating mode :
- Measurement
- Analyze Data
- Parameters
- User Management
ZetaQ control interface
- All information (Sample, Device, SOP, Measurements, etc.) accessible on the same panel
- No tedious cascaded menus or scrolling bars
- Measurements started and analyzed with few clicks
Three different user settable kinetic modes : ζ vs. time, ζ vs. pH, ζ vs. sample Temperature
Three measurement resolutions: Low (<1 mv), Medium (<0.5 mv), High (<0.1 mv).
The data Viewer
Advanced data-viewer for data post-processing :
- Select experiments results and data from different users databases
- Visualize them separately or superimposed on the same graph in the Analysis page
- Display fits, zoom, select or discard results, change the solvent properties, etc
The Analysis page
- Zeta potential and mobility measurements with their fits, averaged values and sigma (standard deviation) for each experiment displayed
- Possibility to select or discard individual measurements
- Possibility to save experiment results and create report
Embedded Solvent Database
It contains :
- About 100 referenced solvents
- Refractive index, viscosity and dielectric constant data vs. temperature
- Import your selected solvent proper ties in just one click
- Create and add your own solvent to the database
- Define its characteristics vs. temperature with various predefined interpolation models
The User management tool
- Create/edit user’s profile (First name, login , password, etc)
- Three different categories of users (admin, expert, operator)
- Define access level to software advanced functionalities
Automatic measurement report editor
- Visualize, edit, print and save a complete measurement report
- Contains all sample and measurement results information
- Generated in just one click
ZetaQ integrates many other advanced functionalities (customizable report edition, measurement replay mode, advanced analysis high accuracy mode, ) that we invite you to discover on our video. For more information, please contact us
WALLIS Zeta Potential
| 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 | ||
