Two-point scaling analysis of the isobaric heat capacity of dodecyltrimethylammonium bromide aqueous solutions in the presence of the n-hexan-1-ol as a co-surfactant

Abstract

The specific heat capacities at constant pressure cp of aqueous solutions of cationic surfactant: dodecyltrimethylammonium bromide, with addition of co-surfactant: n-hexan-1-ol with the molar ratio of surfactant to co-surfactant 1:1 have been measured within temperature range (278.15–328.15) K over wide concentration range. The apparent and partial molar heat capacities of the surfactant/co-surfactant were calculated to analyse the aggregation process taking place in the solution. In order to study some additional information on the solution structure and verify the shape of the aggregates the two-point scaling theory was used for the first in the case of the surfactant/co-surfactant system in which prolate micelles are formed.