Unusual dispersion of the electro-optically determined electric polarizability of bentonite dispersed particles in the range 10 kHz — 1 MHz

An unusual dispersion of the electric light scattering by aqueous calcium bentonite is observed. The electro-optic effect rises with the increase of the frequency in the range 10 kHz — 1 MHz. Parallel measurements are made on suspensions of sodium bentonite and zetlizer kaolinite at different ionic strengths and particle dimensions. It is shown that the dispersion for calcium bentonite does not greatly depend on the concentration of the indifferent electrolyte (sodium chloride with concentrations 10^–4 and 5.10^–4 M/l) or on the suspension concentration. Several possibilities for explaning this unusual dispersion are considered.