PARTICLE-SIZE ANALYSIS BY DYNAMIC LIGHT-SCATTERING

Dynamic light scattering is an established technique for measuring the average size and size distribution of particles in a suspension. The technique has the advantage of being fast and non-invasive, but it doe s require low particle concentrations. As well, dynamic light scatteri ng results are often open to misinterpretation if one is unaware of th e state of the sample and the method of data analysis. The following d iscussion reviews some of the basic concepts of dynamic light scatteri ng and outlines some of the pitfalls that are often encountered in dat a interpretation. A modification of dynamic light scattering, diffusin g wave spectroscopy, can be used to obtain approximate size informatio n at higher particle concentrations. The fundamentals of this new tech nique are summarized.