Dielectric spectroscopy of colloidal suspensions : II. Comparisons between experiment and theory
A four-electrode frequency-difference dielectric spectrometer is used to study the dielectric response of suspensions of amphoteric polystyrene particles in dilute HCl solutions. Results are given for one set of particles with relatively thick diffuse layers, i.e., 3 < ?? < 10. When the dielectric spectra are compared to those predicted by classical electrokinetic theory, large discrepancies are found. The measured dielectric constant is an order of magnitude larger than the theoretical value. The limited body of experimental data extant in the literature confirms these results, suggesting that the standard electrokinetic model is somehow deficient when applied to dispersions of this sort.