Detergency colloid science

Traditionally, monolayer and multilayer adsorption have been used in detergency, mineral processing, flotation, stability of food and pharmaceutical emulsions, and the like, and, as a consequence, the topics of this chapter have been a central part of colloid science. In recent years, however, research on monolayer and multilayer deposition has mushroomed rapidly because of significant new opportunities. 

McBain, J.W. Solubilization and other factors in detergent action. In Advances in Colloid Science Interscience New York, 1942 1. 

A.M. Schwartz. The Physical Chemistry of Detergency in Surface and Colloid Science. E. Matijevic. Ed.. Vol. 5 Wiley-lnterscience (1972) 195. 

It may also be mentioned that oriented micelles occur in solutions of Na des-oxycholate too . However the orientation of the molecules is in this case not so easily established as in soap solutions. The lipids exhibit a similar orientation We may pause a moment at the question of what factors determine the detergent action of soap solutions. We will only examine in more detail the solubilisation, as a result of which the dirt is dissolved and taken up into the micelles (for a review of the most important factors in detergent action — solubilisation, emulsification, protective action, base exchaii e, suspending action — see an important article by Me Baust in Advances of Colloid Science ). Hartley imagines that the organic material would be dissolved in the interior of the spherical soap micelles. 

Particle electrophoresis has proved to be very useful in many areas of theoretical and practical interface and colloid science, including model polymer latex and silver halide systems, and more practical problems related to water purification, detergency, emulsion science, the characterization of bacterial surfaces, blood cells, viruses, and so on. With the advent of more sophisticated computer data analysis and laser hght sources, the limits of resolution for particle sizes that can be analyzed has been, and is being, steadily reduced, so that with proper (and more expensive) instrumentation, the electrophoretic nature of particles in the size range of a few nanometers can be readily determined. 

Peper, H. The defoaming of synthetie detergent solutions by soaps and fatty aeids. J. Colloid Science. 1958 13(3) 199-207. 

The application area of surface and colloid science has increased dramatically during the past decades. For example, the major industrial areas have been soaps and detergents, emulsion technology, colloidal dispersions (suspensions, nanoparticles), wetting and contact angle, paper, cement, oil recovery (enhanced oil recovery [FOR] and shale oil/gas reservoir technology), pollution control, fogs, foams (thin liquid films), food industry, biomembranes, membranes, and pharmaceutical industry. 

Detergency is unquestionably a surface and colloidal phenomenon reflecting the physicochemical behavior of matter at interfaces. Since the field is concerned principally with the removal of complex mixtures of soils and oily mixtures from equally complex soUd substrates, it is not surprising that such systems do not lend themselves readily to analysis by the more fundamental theories of surface and colloid science. A rigorous treatment of the current status of detergency theory would constitute a book itself. This section summarizes some of the most important aspects of detergency and illustrates how the chemical structure of the surfactants and other components in a formulation can affect overall performance. 

Molecular Structure Effects and Detergency. The correlation of surfactant structure with interfacial and colloid properties is a poorly understood science. Much study in this area has been thermodynamic which has been a useful endeavor but which nevertheless fails to provide specific molecular structure/physical property correlations. The following study has also been largely thermodynamic to this point however, since the data has been collected on pure LAS homologs, it provides an opportunity to apply some of the quasi-thermodynamic treatments that have been proffered in the literature to date. 

Coke, M., Wilde, P.J., Russell, E.J., Clark, D.C. (1990). The influence of surface composition and molecular diffusion on the stability of foams formed from protein detergent mixtures. Journal of Colloid and Interface Science, 138, 489-504. 

This class of association colloids can be further divided into several subgroups, which include micelles, vesicles, microemulsions, and bilayer membranes. Each subgroup of association colloids plays an important role in many aspects of colloid and surface science, both as theoretical probes that help us to understand the basic principles of molecular interactions, and in many practical applications of those principles, including biological systems, medicine, detergency, crude-oil recovery, foods, pharmaceuticals, and cosmetics. Before undertaking a discussion of the various types of association colloids, it is important to understand the energetic and structural factors that lead to their formation. 

The understanding of the interfacial behavior of aqueous surfactant solutions is a major issue in surface science both from a theoretical and from a technological point of view. On the one hand, the interpretation of several colloid phenomena requires detailed knowledge of the adsorption layer of the system [1] on the other hand, the performance of many commercial products and industrial technologies (e.g. detergents, pharmaceutical applications, food and mineral processing, oil recovery) [2] is based on the adsorption of surfactant molecules. This explains the widespread interest in surfactant adsorption studies and the fact that this phenomenon is still the subject of intensive experimental and theoretical investigation [3]. 

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