Thermodynamics of micellization of surfactants of low aggregation number: The aggregation of propranolol hydrochloride

The self-association of propranolol hydrochloride in aqueous solution has b een studied as a function of temperature, The critical concentration (C*) a nd the degree of ionization (alpha) were determined by conductivity measure ments at temperatures over the range 298.15 to 313.15 K. The enthalpy chang e on aggregation in water was measured by microcalorimetry. To calculate ch anges in the thermodynamic properties of aggregation the mass action model for high and low aggregation numbers was applied, the latter model giving b etter agreement between experimental and theoretical enthalpy changes. (C) 1999 Academic Press.