Partial molal volumes and compressibilities of sodium-alkylcarboxylates, disodium-alkyldicarboxylates, and N-diols in micellar solutions of sodium-alkylcarboxylates at 25°C

Abstract

Partial molal volumes and compressibilities of sodium-alkylcarboxylates, disodium-alkyldicarboxylates, and n-diols in micellar solutions of sodium-alkylcarboxylates have been determined at 25°C. The partial molal volumes were determined from density measurements, and the partial molal compressibilities were determined from ultrasound measurements. The obtained partial molal quantities for n-diols are similar to those in liquid hydrocarbon. The corresponding quantities for the alkylcarboxylates and alkyldicarboxylates are higher than those in water, but smaller than expected if these molecules were completely solubilized in the micelles. The degree of solubilization for these molecules has been discussed. From the obtained partial molal volumes and compressibilities additivity relations for group partial molal quantities in the micellar phase have been established.