Abstract
In order to make clear the mechanism of solubilization of water in nonaqueous solutions of dodecylammonium carboxylates, the vapor pressure of water solubilized by dodecylammonium propionate, butyrate, valerate, and caproate and the temperature dependence of the vapor pressure were measured, especially noting the initial stage of solubilization. The heat of solubilization (ΔHs) calculated from the measurement of the temperature dependence showed smaller values than the heat of condensation of water (ΔHw) in the initial stage of solubilization. ΔHs increased and exceeded ΔHw with addition of water. The solvent dependence of the ΔHs by dodecylammonium butyrate was observed in the initial stage of solubilization.
The change of ΔHs with the amount of added water was explained with reference to the results of the NMR measurement of the carbon tetrachloride solution and water-solubilizing solution of dodecylammonium butyrate reported by Yan et al.
