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Title: Apparent modal volumes and heat capacities of ionic surfactants in water at 25/sup 0/C

Journal Article · · J. Colloid Interface Sci.; (United States)

One of the main objectives of most studies of the thermodynamics of surfactant solutions is the understanding of the factors governing the formation of micelles. Currently, the thermodynamic analysis of micellization is in an unsatisfactory state. Of the 3 main approaches--mass action, phase separation, and small-system thermodynamics--the latter seems the most promising, but as yet no one approach is applicable to all systems. In general, a relation is established between the standard free energy of micellization and the critical micelle concentration (CMC), and between the standard enthalpy of micellization and the temperatures dependence of the CMC. The densities and volumetric specific heats of some cationic and anionic surfactants were measured with the flow digital densimeter and a flow microcalorimeter in water at 25/sup 0/C in the concentration range 0.01 to 0.7 m. The systems studied were sodium octyl, decyl and dodecyl sulfate, nonyl and decyl trimethylammonium bromide. (28 refs.)

Research Organization:
Sherbrooke Univ.
OSTI ID:
5006508
Journal Information:
J. Colloid Interface Sci.; (United States), Vol. 48:3
Country of Publication:
United States
Language:
English