Effect of alcohols on the CMC and thermodynamic functions of anionic Surfactants in DMF/long-chain alcohol using microcalorimetric method

摘要

The critical micelle concentration (CMC) of two kinds of anionic surfactant (including sodium laurate (SLA) and sodium dodecyl sulfate (SDS)) in mixed alcohol and N, N-dimethyl formamide solvent (DMF) were investigated through measuring power-time curves by titration microcalorimetry. From data of the lowest point and the area of the power-time curves, their CMC and Delta H-m(0) can be obtained. According to standard thermodynamic equations, AGO. and Delta S-m(0). also can be calculated. For different surfactant, the influences of the carbon number and the concentration of alcohol on the CMC and standard thermodynamic functions are different in DMT polar medium. These thermodynamic functions for micelle formation can be further interpreted.