Abstract: Dielectric measurement was carried out on the polystyrene(PSt) suspensions in electrolyte aqueous solution with different concentration. A couple of dielectric relaxations were found in frequency range from 40 Hz to 110 MHz. On the basis of dielectric model, theoretical analysis for the mechanism of the two relaxations show that low(kilohertz) and high-frequency(megahertz) relaxation were respectively attributed to the diffusion of counter ions in electrical double layer and to the accumulation of space charges on phase interface. Phase parameters and electric information of the microsphere interior were estimated from the relaxation parameters by using Hanai's equation, and reasonable explication was suggested. The validity of the model and method used in this work have been examined by theoretical calculation.

Key words: Polystyrene suspension, Dielectric relaxation spectroscopy, Interfacial polarization, Electrical double layer, Surface conductivity