Solubilization of benzene in certain detergent solutions that appear to give two different values

Abstract

Far below saturation of a soap solution with solubilized benzene or toluene there is a zone of maximum turbidity caused by the formation of acid soap which is largely resorbed in the micelle before true saturation is reached. The phenomenon has been observed with potassium laurate, dodecylamine hydrochloride, and cetyl pyridinium chloride, all of which are hydrolyzable, but not with sodium lauryl sulfate, where hydrolysis is absent. The material causing the turbidity has been centrifuged out in the case of potassium laurate and has been found to be pure acid soap, HL·KL, containing no benzene. The maximum in turbidity in this intermediate zone is accompanied by a maximum in pH. This intermediate turbid region tends to be suppressed by all factors that reduce hydrolysis or solubilize the products of hydrolysis. These are high alkalinity in the case of ordinary soaps, high concentration of soap or detergent, and high temperature, where the amount of solubilization is greatly increased. A mechanism is suggested which might cover the known facts.