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Light scattering is the consequence of interactions
of light with matter. Photons of light travel in a
straight line. When they encounter a particle of
matter, the light scatters. Dynamic light scattering
measures the deflection of light at a specific angle
and how it changes over time. This information is
used to calculate the size of a particle.
The key information needed for a DLS measurement is the intensity
of the scattered light. This ultimately allows determination of the
diffusion coefficient D of the particles, which is used to calculate
the average particle radius and the distribution of particle sizes in
solution. The factors that contribute to the ultimate intensity of the
scattered light are the intensity and wavelength of incident light, as
well as particle motion. They are described in detail below.
