Topics in Particle and Dispersion Science

Diffusion of particles via Brownian motion depends on particle size. This is used to determine the particle size distribution (PSD) of suspensions via the dynamic light scattering (DLS) (for example, Finsy 1994). In this method, the correlation of light scattered by a large number of particles is measured.

Finder et al (2005) developed a measurement system, which determines the diffusion coefficients (see Dynamic light scattering), and thus the sizes (here EHDs) of many particles simultaneously by tracking movements of individual particles via automated analysis of a series of images. This permits one to determine the PSD in a particle size range of 50 to 1000 nm (EHD).

The diffusion coefficient (see Dynamic light scattering) of a single particle has been also measured via optical particle tracking (for example, Schätzel et al 1992, see also Single particle tracking).