| Popis: |
The thermodynamics of micellar solubilization of benzyl alcohol in binary surfactant solutions of two cationic surfactants, benzyldimethyletradecylammonium chloride and trimethyletradecylammonium chloride (I) have been deduced from precise calorimetric measurements at controlled solute activity. Although the critical micelle concentration (CMC) of the surfactant mixtures display a nearly ideal behavior, the partition coefficient P between mixed micelles and water, as well as the standard enthalpy of transfer of benzyl alcohol between micelles and water present several extrema. These peculiar results are compared to those obtained previously for 1-pentanol in anionic + cationic (II) are anionic + nonionic (II) surfactant systems. It is shown that the regular solution formalism may be used to represent systems (II) and (III), assuming binary interactions between the surfactants, whereas for system I, ternary interactions between the surfactants are needed. A tentative moelcular interpretation of the data is proposed. |
