Micellization of dodecyldimethylethyl-ammonium bromide in aqueous solution -: Thermal parameters

Specific conductivity of aqueous solutions of dodecyldimethylethylammonium bromide has been determined in the temperature range of 15-40degreesC. The critical micelle concentration (cmc) and ionization degree of the micelles, beta, were determined from the data. Thermodynamic functions, such as standard Gibbs free energy, DeltaGdegrees(m), enthalpy, DeltaH(m)(o), and entropy, DeltaS(m)(o), of micellization, were estimated by assuming that the system conforms to the mass action model. The change in heat capacity upon micellization, DeltaC(p,m)(o), was estimated from the temperature dependence of DeltaH(m)(o). An enthalpy-entropy compensation phenomenom for the studied system has been found.