Analytical Methods | Light Scattering Techniques

A brief introduction to light scattering is followed by examples of the behavior encountered in static light scattering with samples of increasing size relative to the wavelength of the incident light. The principles of dynamic light scattering are explained. Applications considered include measurement of casein micelle size and enzyme-induced aggregation, as well as measurements of fat globule size in whole and homogenized milks. Problems encountered in highly multiple-scattering opaque systems, such as undiluted milk, are considered next and the technique of diffusing wave spectroscopy (DWS) is introduced. Like dynamic light scattering, DWS gives a measure of the mobility of the scattering entity, but in a concentrated system, mobility is influenced by other factors besides size. Various examples of behavior encountered in emulsions, during aggregation and gelation, are given.