Director, Materials Characterization Lab
The Malvern Zetasizer ZS90 measures the size and size distributions of particles in solution using dynamic light scattering (DLS). The effective hydrodynamic size of particles measured by this technique can be from 0.3nm to 5µm depending on the relative difference in refractive index for the particle and solution. The molecular weight and second virial coefficient of larger particles can be determined using the Debye method or the Mark-Houwink equation. The instrument is also equipped for the measurement of zeta potentials (electrophoretic mobility) of colloidal dispersions. The zeta potential provides information about how stable such dispersions are over time (will they aggregate over time or not).