STUDY OF THE AGGREGATION OF DECYLAMMONIUM CHLORIDE IN AQUEOUS-SOLUTIONS IN THE PRESENCE OF SODIUM-CHLORIDE BY VAPOR-PRESSURE OSMOMETRY

Osmotic coefficients were calculated from vapor pressure osmometry measurements made on aqueous solutions of decylammonium chloride in the presence of sodium chloride at 30°C. At surfactant concentrations below the critical micelle concentration (CMC), deviations from ideal behavior were relatively small and were described by an extended form of the Debye-Hückel equation. Concentrations higher than the CMC resulted in deviations chiefly arising from aggregation phenomena. We discuss the influence of the so-called degree of counterion binding, a parameter used in equations for calculating the osmotic coefficients of micellar solutions. © 1991.