Details
- Properties that can be measured by Zetasizer are (1) Particle Size and (2) Zeta potential measurements.
- Particle size analysis- The Zetasizer system determines the size by first measuring the Brownian motion of the particles in a sample using Dynamic Light Scattering (DLS) and relates this to the size of the particle. Brownian motion is the movement of particles due to the random collision with the molecules of the liquid that surrounds the particle. An important feature of Brownian motion for DLS is that small particles move quickly and large particles move more slowly. The relation between the size of the particle and its speed due to Brownian motion is defined in the Stokes-Einstein equation.
- Zeta potential measurements- Zetasizer calculates the zeta potential by determining the electrophoretic mobility and then applying the Henry equation. The electrophoretic mobility is obtained by performing an electrophoresis experiment on the sample and measuring the velocity of the particles using Laser Doppler Velocimetry (LDV).
Model and Make
Nano ZS90 (green laser), Malvern Ltd UK
Specifications
- Size range for Particle size analysis: 1nm to 3 nm (diameter)
- size range for Zeta potential: 5nm to 10 nm (diameter)