Electrokinetic Phenomena in Electrical Insulating Oil/Impregnated Cellulosic Pressboard Systems

A new method has been developed for measuring the zeta potential which exists on the surface of cellulosic pressboard impregnated with electrical insulating oil, while the oil streams through the capillary holes in the pressboard. The metal salts of di-(2-ethyl-hexyl) sulphosuccinate were dissolved in a purified insulating oil, and the zeta potential and the ac conductivity here investigated. The dependence of the zeta potential on the type and concentration of the salt was clarified. Electrokinetic phenomena in insulating oil are identical with those in aqueous solutions.