MECHANISM OF SOLUBILIZATION OF WATER BY OIL-SOLUBLE SURFACTANT SOLUTIONS .2. CATIONIC SURFACTANTS

The vapor pressure of water solubilized by didodecyldimethyl ammonium chloride, bromide, or iodide in benzene or tetrachlorethylene and its temperature dependence were measured. The limiting amount of water solubilized (S0) and the heat of solubilization (ΔHS) were obtained from the measurement. The micellar weight (M) of these surfactants was also measured. The order of magnitude of S0, ΔHS, and M was chloride > bromide > iodide. Solubilization of water is partly explained by the ion-dipole interaction between the water molecule and the halogen anion, but the acid-base interaction also needs to be taken into consideration. © 1969.