STUDIES ON MICELLE FORMATION AND ENTHALPY OF MICELLIZATION IN MOLTEN ACETAMIDE

The electrical conductivity of lithium dodecylsulfate, sodium dodecyls ulfate, sodium oleate and sodium stearate has been determined in molte n acetamide at 90 degrees C. Conductivity measurements show that for t hese surfactants, micelles are formed in molten acetamide solutions. T he critical micelle concentration (CMC) of each surfactant has been ca lculated. Lithium dodecylsulfate has a lower CMC than sodium dodecylsu lfate. Sodium oleate, which contains a double bond and has the same nu mber of carbon atoms as sodium stearate, has a lower CMC. The enthalpy of micellization for sodium oleate in molten acetamide has been found by determining the CMC at different temperatures. The results have be en explained on the basis of solvation effect and nature of micelles.