Photon Correlation Spectroscopy, Transient Electric Birefringence, and Characterization of Particle Size Distributions in Colloidal Suspensions

摘要

By using a combination of static and dynamic laser light scattering and transient electric birefringence we have been able to determine structural characteristics and size distributions of polydisperse disk-shaped particles (bentonite) in suspensions. In the limit of low concentration and scattering angle we obtained the weight-average molecular weight, the z-average radius of gyration and the second virial coefficient from static light scattering measurements; at higher scattering angles we were able to estimate an average particle thickness. Photon correlation function measurements of both the polarized and the depolarized components of scattered light give us the average diffusion coefficients (translational) and (rotational) which can in turn by converted to average particle dimensions. Detailed analysis of characteristic linewidth distributions yield particle size distributions consistent with direct observations using electron microscopy.