Properties of surfactant solutions

F. M. Fowkes, in Solvent Properties of Surfactant Solutions, K. Shinoda, ed., Marcel Dekker, New York, 1967. 

Critical Micelle Concentration. The rate at which the properties of surfactant solutions vary with concentration changes at the concentration where micelle formation starts. Surface and interfacial tension, equivalent conductance (50), dye solubilization (51), iodine solubilization (52), and refractive index (53) are properties commonly used as the basis for methods of CMC determination. 

Solvent Properties of Surfactant Solutions, edited by Kozo Shinoda (see Volume 55)... 

Properties of Surfactant Solutions in Equilibrium with an Adsorbent Solid... 

In Section 8.2 we are concerned with the threshold concentration of surfactants at which micellization occurs. This concentration, known as the critical micelle concentration (CMC for short), is one of the most important properties of surfactant solutions. We look at two different ways of modeling micellization and discuss briefly when they are appropriate. 

Also included in Chapter 18 is a discussion of ion association at high temperatures and the properties of surfactant solutions, which are described in terms of the pseudo-phase model and the mass action model. 

CMCs in the absence of added electrolyte may be greatly influenced by electrovis-cous effects marked decreases in intrinsic viscosity on electrolyte addition have been observed in many cases36). Peculiar and highly interesting rheological properties of surfactant solutions include observations of strongly non-Newtonian behavior as well as of viscoelasticity these are yet incompletely understood. 

Fowkes, F. M. In Solvent properties of surfactant solutions. Shinoda, K. (ed.). New York Dekker 1967... 

Hoffmann, H. (2000) The micellar structures and macroscopic properties of surfactant solutions. In H. Hoffmann, M. Schwoerer and Th. Vogtmann (eds). Macromolecular Systems Microscopic Interactions and Macroscopic Properties. Wiley-VCH, pp 199-250. 

Shinoda, K. "Solvent Properties of Surfactant Solutions" Marcel Dekker, Inc. New York, 1967. 

An early attempt to correlate the physical properties of surfactant solutions and their foams with oil recoveries was performed by Deming in 1964 (50). Deming concluded that high foaming ability favored high displacement efficiency, but that high foam stability were not required for high displacement efficiency. Bernard and Holm found that oil substantially decreased the abilities of most surfactants to reduce aqueous permeabilities, but that some surfactants remained effective even in the presence of oil (52,53). 

A universal property of surfactant solutions is the existence of a critical micelle concentration (CMC) representing the minimum amount of surfactant required to form aggregates. The CMC also represents the solubility of the surfactant unimer in the oil or continuous phase solvent. At surfactant concentrations above the CMC,... 

The current state OF THE ART of various aspects of macro- and microemulsions is reflected in this volume. The symposium upon which this volume is based was organized in six sessions emphasizing major areas of research. Major topics discussed include a review of macro- and microemulsions, enhanced oil recovery, reactions in microemulsions, multiple emulsions, viscoelastic properties of surfactant solutions, liquid crystalline phases in emulsions and thin films, photochemical reactions, and kinetics of microemulsions. 

Table I shows various surface and microscopic properties such as surface tension, surface viscosity, foaminess (i.e. foam volume generated in a given time) and bubble size in foams of the surfactant solutions as a function of chain length compatibility. The results indicate that a minimum in surface tension, a maximum in surface viscosity, a maximum in foaminess and a minimum in bubble size were observed when both the components of the mixed surfactant system have the same chain length. These results clearly show that the molecular packing at air-water interface influences surface properties of the surfactant solutions, which can influence microscopic characteristics of foams. The effect of chain length compatibility on microscopic and surface properties of surfactant solutions can be explained as reported in the previous section.

Almost from the very beginning of the study of the properties of surfactant solutions (actually, soap solutions), it was recognized that their bulk properties were unusual and indicated the presence of colloidal particles in the solution. 

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