Binary anionic surfactant

LOPATA ET AL. Adsorption of Binary Anionic Surfactant Mixtures... 

Consider the formation of a mixed micelle in aqueous solution from a binary surfactant solution consisting of a nonionic and an anionic surfactant. The process is depicted as the aggregation of ng molecules of nonionic surfactant B, of n molecules of anionic surfactant A", and in addition there will be counterions, C" ", of the anionic surfactant in the amount of an where a is the fraction of the counterions associated or bound with the surfactant anions in the micelle. The process as depicted is... 

Scamehorn et. al. (19) reported the adsorption isotherms for a binary mixture of anionic surfactants. A formal adsorption model developed for single surfactant systems ( ) was extended to this binary system and shown to accurately describe the mixed adsorption isotherms (19). That theoretically based model was very complex and is probably not feasible to extend beyond two surfactant components. 

Scamehorn, J.F., Schecter, R.S. and Wade, W.H. (1982) Adsorption of surfactants on mineral oxide surfaces from aqueous solutions. II. Binary mixtures of anionic surfactants. /. Colloid Interface Sci., 85, 479-93. 

The adsorption of binary mixtures of anionic surfactants of a homologous series (sodium octyl sulfate and sodium dodecyl sulfate) on alpha aluminum oxide was measured. A thermodynamic model was developed to describe ideal mixed admicelle (adsorbed surfactant bilayer) formation, for concentrations between the critical admicelle concentration and the critical micelle concentration. Specific... 

Scamehorn et. al. expanded a single component adsorption equation ( ) to describe the adsorption of binary mixtures of anionic surfactants of a homologous series (1 1). Ideal solution theory was found to describe the system fairly well. The mixed adsorption equations worked very well in predicting the mixture adsorption, but the equations were complex and would be difficult to extend beyond a binary system. 

The adsorption of binary mixtures of anionic surfactants in the bilayer region has also been modeled by using just the pure component adsorption isotherms and ideal solution theory to describe the formation of mixed admicelles (3 ). Positive deviation from ideality in the mixed admicelle phase was reported, and the non-ideality was attributed to the planar shape of the admicelle. However, a computational error was made in comparison of the ideal solution theory equations to the experimental data, even though the theoretical equations presented were correct. Thus, the positive deviation from ideal mixed admicelle formation was in error. 

Scamehorn, J. F., R. S. Schechter, and W. H. Wade (1982b), Adsorption of Surfactants on Mineral Oxide Surfaces from Aqueous Solutions. II. Binary Mixtures of Anionic Surfactants, J. Colloid Interface Sci. 85, 479-493. 

Mixture of Anionic Surfactants onto Alumina. Most EOR surfactants are mixtures of isomers, but these mixtures are too complex for application of basic theory. In contrast, the effectiveness of ideal solution theory in explaining region II adsorption for binary mixtures of anionic surfactants has been demonstrated [5Jj. These controlled isomeric mixtures allow application of the ideal solution theory. The application of this theory utilized a reduced adsorption equation for mixtures of anionic surfactants [52]. The parameters for this reduced... 

The protective effect of protein derivatives in detergency has been tested in numerous studies and quantitative data are available in the technical literature. Native proteins, hydrolysates, and condensates are all reported to reduce the irritant effects of tenside on the skin. To compare the protective properties of protein substances with the well-known effect of amphoteric and nonionic tenside in detergent formulations based on anionic surfactants, a study was carried out based on intensive and repeated application on the skin of binary systems containing sodium lauryl sulfate and the anti-irritant test substance, and evaluation of some biophysical parameters for assessing skin damage (122). It was demonstrated that a hydrolyzed protein was as effective as some of the cosurfactants traditionally employed to inhibit the irritation potential of anionic tensides. Some of the results obtained are illustrated in Figure 29. 

Figure 4 shows the binary diagram for the quintessential anionic surfactant, sodium dodecyl sulfate (SDS) in water... 

In Chapter 1, Murgia, Palazzo, and coworkers investigated the physicochemical behaviors of a binary IL bmimBF and water, and the ternary NaAOT, water and bmimBF mixtures essentially through the evaluation of the self-diffusion coefficients of the various chemical species in solution by PGSTE-NMR experiments. The diffusion of water molecules and bmimBF ions were found to be within different domains, which suggested that the systems were nanostructured with formation of micelles having positive curvature and a bicontinuous micellar solution for the former and the later systems, respectively. The remarkable differences between the two systems are attributed to the specific counterion effect between the aforementioned ILs and the anionic surfactant. In Chapter 2, Bermudez and coworkers focused on the characterization of small (conventional surfactants) and polymeric amphiphiles (block copolymers) in different types of ILs (imidazolium, ammonium. 

Masukawa and Tsujimura (1997) patented a method to determine surfactants in cosmetic products by reversed-phase LC without pre-treatment. Chromatographic conditions involved a binary gradient with methanol and water, ammonium carbonate salt as buffer and LSD detection. Amphoteric surfactants (Cg-Ci6 amidobetaines), an anionic surfactant (Cl2-16 acylmethyltaurine) and two types of nonionic surfactants (Cg i4 diethanolamides and Ci2 14 alkyl polyoxyethylene alcohols) were identified on applying this method. 

Whether an emulsion is 0/W or W/0 depends on a number of variables like oihwater ratio, electrolyte concentration, temperature, etc. For most of this centiuy, emulsion chemists have known that surfactants more soluble in water tend to make 0/W emulsions and surfactants more soluble in oil tend to make W/0 emulsions. This is the essence of Bancroft s rule, which states that the continuous phase of an emulsion tends to be the phase in which the emulsifier is preferentially soluble. The word soluble is misleading, however, for two reasons. Firstly, a surfactant may be more soluble in, say, oil than in water in a binary system, but in the ternary system of oil -I- water + surfactant it may partition more into water. A good example of this is with the anionic surfactant Aerosol OT (sodium bis-2-ethylhexylsulfosuccinate) which dissolves in heptane at 25 C up to at least 0.5 m but has a solubility limit in water of only 0.03 M. An emulsion made from equal volumes of water and heptane at 25 °C is 0/W, however. Secondly, no distinction is made between the solubility of monomeric or aggregated surfactant in oil or water. We will see that this is an important omission. 

Binary hydrocarbon surfactant systems consisting of an anionic and a nonionic surfactant with almost equal cmc values generally exhibit a minimum cmc in the cmc versus composition curve. This negative deviation from the ideal cmc-com-... 

In the most recent method described by Hu et al. [239] for the direct determination of ultraviolet-absorbing inorganic anions in saline matrixes, an octadecylsilica column modified with a zwitterionic surfactant [3-(N,N-di-methylmyristylammoniojpropanesulfate] is used as the stationary phase, and an electrolytic solution is used as the eluent. Under these conditions, the matrix species (such as chloride and sulfate) are only retained weakly and show little or no interference. It is proposed that a binary electrical double layer is established by retention of the eluent cations on the negatively charged (sulfonate) functional groups of the zwitterionic surfactant, forming a cation-binary electrical double layer. 

Bourrel M, Bernard D, Graciaa A (1984) Properties of binary mixtures of anionic and cationic surfactants Micellization and Microemulsions. Tenside Deterg 21 311-318... 

The deviation From ideality For binary pairs oF surFactants increases in the order cationic/nonionic, anionic/nonionic, anionic/cationic. 

The variation of the mixture critical micelle concentration (CMCf ) with temperature and with overall surfactant composition has been studied using ultrafiltration for two binary mixed nonionic/anionic systems. 

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