Model: Wallis
NSX: Cordouan - Pháp
WALLISζTM is an innovative high resolution Zeta potential analyzer purely dedicated to nanoparticle and colloidal charge characterization.
Dip cell : simple, robust, artifact-free
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.
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.
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 |