Low-frequency dielectric response of a single particle in aqueous suspensions

$\alpha -$relaxation, the counterion diffusion in the electric double layer, has been used to described the anomalous low frequency dielectric dispersion of aqueous suspensions of colloidal particles. A microscopic theory describing this relaxation process proposed by Schwarz, however, has not been investigated systematically. We propose to use a single particle dielectrophoresis (DEP) force spectroscopy to study the relaxation mechanism as a function of particles size, temperature and solvent viscosity. Specifically, we measure the dependence of the DEP crossover frequency force and compare results with predictions by Schwarz.