Malvern Zetasizer Nano ZS
Malvern Zetasizer combined 3 major techniques:
1. Dynamic Laser Scattering for Particle Size measurement
2. Static Laser Scattering for Mw measurement
3. Zeta-potential measurement
Equipped with MPT-2 autotitrator and temperature control system, the Zetasizer Nano is capable for pH titration, sample dilution and injection, temp. trend measurements and melting point studies. Please refer to User Manual to learn more about zetasizer.
* (2010-04-02) Cuvettes should be rinsed and sonicated in your buffers and/or ddH2O before applying samples for measurements.
* (2009-09-02) Please avoid dusts or contaminate when preparing your sample. Do not transfer samples from container to container, which introduces dusts and bubbles.
Dynamic Light Scattering*
Dynamic light scattering (DLS) also known as Photon Correlation Spectrpscopy (PCS). By detecting the laser scattered from solution, the velocity of Brownian motion could be used for calculating the size of the particle. Please refer to Dynamic Light Scattering at Malvern website for details.
Static Light Scattering
Like DLS, Static light scattering (SLS) also measures the scattered light. But, instead of measuring the time-dependent fluctuations in the scattering intensity, SLS makes use of the time-averaged intensity of scattered light instead. When particles in solution are much smaller than the wavelength of the incident light, the angular dependence of the scattering intensity is lost. The type of scattering is known as Rayleigh scattering. The intensity of scattered light produced by particles is propotional to the product of weight-average Mw and the concentration of the particle. By measuring the Intensity of scattered light of various concentration at 1 angle, the Debye Plot is presnt to allow the determination of both absolute Mw and 2nd Virial Coefficient.
The net charge at the particle surface affects the distribution of ions in the surrounding, thus forming an electrical double layer around each particle. When a particle moves, ions within the boundary move with it, and vice versa. Zeta potential is the potential that exists at this boundary. The intensity of the Zeta potential is an indication of the potential stability in the collidal system. Particles with zeta potentials between +30mV and -30mV are normally considered unstable. .
* Pictures adepted from Manuals of manufacturer.
|Particle size range||0.6nm - 6μm|
|size range for zeta potential||5nm - 10μm|
|size range for Mw||1000 - 2x10^7 Da|
|Temperature range||2-90 ℃|
Recommended Sample concentration
|Particle size||Min. concentration||Max. concentration|
|< 10 nm||0.5g/l||---------------|
|10nm - 100nm||0.1mg/l||5% mass|
|100nm - 1μm||0.01g/l||1% mass|
|> 1μm||0.1g/l (0.01% mass)||1% mass|