Electrophoresis of colloidal copper phthalocyanines in low permittivity liquids

Abstract

The electrophoretic behaviour of colloidal β-copper phthalocyanine and monochloro substituted α-copper phthalocyanine dispersed in heptane and benzene has been investigated. Changes in zeta potential with concentration of anionic (Aerosol OT) and cationic [di-(2-ethylhexyl)ammonium chloride] surfactant, and the surfactant adsorption isotherm have been determined. In addition, the effects on the electrophoretic mobility of the polar additives water and methanol have been examined. It is suggested that the zeta potential in the presence of small amounts of polar additives is primarily determined by the extent of counter ion penetration into the inner regions of the double layer. In consequence it may be invalid to approximate the surface potential to the zeta potential in systems of this type.