Micelles. Physical chemistry of surfactant association

Micellar solutions as reaction media

The thermodynamics of micelle formation of ionic surfactants, sodium dodecyl sulfate (SDS), cetyl pyridinium chloride (CPC), and sodium salt of dioctyl sulfosuccinate (Aerosol OT or AOT) have been thoroughly assessed from microcalorimetric, conductometric, and tensiometric measurements, and the results have been rationalized in terms of physicochemical concepts and relations. The past and recent critical micellar concentration (CMC) data on SDS have been considered and compared; the CMCs of SDS, CPC, and AOT determined in this and earlier studies have been processed to evaluate the energetic parameters (free energy, enthalpy, entropy, and heat capacity) of micellization. The effect of the salt, NaCl, on the CMC and energetics of micellization of the surfactants has been also examined.

Thermodynamics of Micelle Formation of Ionic Surfactants: A Critical Assessment for Sodium Dodecyl Sulfate, Cetyl Pyridinium Chloride and Dioctyl Sulfosuccinate (Na Salt) by Microcalorimetric, Conductometric, and Tensiometric Measurements

Toward a better understanding of the driving force for micelle formation and micellar growth

The self-aggregation of sodium dodecyl benzene sulfonate (SDBS) and its solution behaviors have been critically assessed by conductometric, tensiometric, spectrophotometric, flourimetric, and calorimetric methods. The interfacial adsorption behaviors of SDBS have also been assessed critically. Based on the isothermal titration calorimetric (ITC) measurements, the thermodynamics of micellization of SDBS have been examined in the light of both “mass action” and “pseudophase” principles. A method of simulation has been used to evaluate the aggregation number and the free energy of micellization according to the mass action model. The thermodynamic parameters derived indirectly from the rationale of van't Hoff and directly by microcalorimetry have been compared and discussed. The interaction of SDBS with the water-soluble polymers poly(vinyl pyrrolidone) (PVP), the chloride salt of the N,N-dimethyl-N-methyl derivative of hydroxyethylcellulose (JR 400), and the chloride salt of the N,N-dimethyl-N-dodecyl deriv...

A critical assessment of micellization of sodium dodecyl benzene sulfonate (SDBS) and its interaction with poly(vinyl pyrrolidone) and hydrophobically modified polymers, JR 400 and LM 200

Marilyn F. Holtzer

Papers

Use of the van't Hoff relation in determination of the enthalpy of micelle formation