Hydrophobic bond in micellar systems. Effects of various additives on the stability of micelles of sodium dodecyl sulfate and of n-dodecyltrimethylammonium bromide

Critical micelle concentrations of aqueous surfactant systems

“…1 The more surface active the monomer is, the higher is the tendency to form micelles and the lower the CMC value. Since above the CMC the monomer activity rises only very 1 Italicized figures in brackets indicate the literature references on page 20. slowly, the CMC is also a measure of the concentration at which the thermodynamic activity of the monomer and, therefore, its net surface activity and adsorbability to various substrates, level off to nearly constant values [7 -3] For the quantitative study of the thermodynamics of the interactions involved in the monomer-micelle equilibrium, the CMC is of paramount importance [16][17][18][19][20][21] [22][23][24]. Such interactions are involved in a wide variety of biochemical phenomena, e.g., the stability, structure, conformation, and activity of proteins, enzymes, and membranes.…”

“…3. There is a variety of methods to investigate optical and spectroscopic properties of a solution, and they may be classified as follows: (a) Measurements of scattered light Conversely the CMC may be obtained by selecting the value which gives the best straight line on such a DEBYE PLT (25). In light scattering the exact procedure was not indicated only once -UNSPEC (1 Calorimetric methods used to obtain CMC's are those of SPECIFIC HEAT (4) and HEAT OF DILUTION (24). 5. Two colligative properties have been used.…”

The Use of Sodium 10-Undecylenyl Sulfate Oligomer and Sodium 10-Undecenoic Acid Oligomer as Pseudostationary Phases in Micellar Electrokinetic Chromatography

“…However, the micelle has a dynamic structure, 3 and the properties of the micelle, e.g., the critical micelle concentration (CMC), aggregation number, and micelle size, are strongly affected by the total concentration of the surfactant, pH, temperature, additives, and composition of the background solution. 4 Recently, high-molecular-mass surfactants (HMMSs) have been employed as pseudostationary phases in MEKC. [5][6][7][8][9][10][11][12][13][14] Since an HMMS forms a molecular micelle which consists of one molecule, and the CMC value is ideally zero, one can expect a higher repeatability in an HMMS-MEKC system compared to an LMMS-MEKC system.…”

Effect of urea on biomimetic aggregates

“…Given the straightforward nature of simple surfactants and the various macromolecular aggregates which can be formed, the effect of urea upon surfactant mixtures has been investigated to determine the physicochemical origins of its action (10)(11)(12)(13)(14)(15)(16). In the present article, we will review the progress made by our research group towards the understanding of what urea does to aqueous solutions (complete details of the data presented here can be found in the original publications cited in Refs.…”