Electrophoretic mobility and dielectric response measurements of colloidal hematite

Abstract

Dielectric response measurements conducted on two different particle sizes (25 and 44 nm radius) of colloidal hematite are reported. The dielectric response signals are much larger than predicted from the theory of Mangelsdorf and White (J. Chem. Soc. Faraday Trans. 86, 2859 (1990)) using the mobility interpreted electrokinetic potentials for both particle sizes. The dielectric loss spectra for the smaller particles, 25 nm radius, appear to show two dispersion frequencies. The low-frequency dispersion has not been observed previously. © 1994 Academic Press, Inc.