Particle size measurement in concentrated latex suspensions using fibre-optic photon correlation spectroscopy

Describes the use of a bifurcated fibre-optics bundle as a light transmission guide to measure the autocorrelation function of light dynamically backscattered from within aqueous suspensions of micron-sized polystyrene latex particles. The measurements cover the volume fraction range from phi approximately 10 -3 to phi approximately 0.1. Exploiting the diffusive nature of the passage of light within such systems, it is demonstrated that such measurements provide a valuable estimate of particle size for a wide range of diameters from 0.1 to 6 mu m. By making measurements on mixtures of the monodisperse lattices, an empirical weighting function is derived to take account of the effects of polydispersity in particle size.