Surfactant mixtures

A surfactant mixture having an HLB number of 8 should give a good W/O emulsion in which the oil phase is lanolin. Suggest two possible surfactant mixtures that you, an aspiring cosmetic chemist, might use you have been told that your formulations must contain 10% cetyl alcohol. 

The gravity measurements of the pelobischofite and appropriate compositions detergency showed the essential increase of this parameter for pelobischofite-surfactant mixtures. Thus the washing power of pelobischofite-surfactant solutions with concentration 0,1% was 90%. Erom another hand, similar detergency of bischofite-surfactant mixtures was reached for 1% solutions only. 

The pelobischofite-surfactant mixtures emulsifying ability was estimated by measurements of the phase immiscibility time for standard oil in water emulsion. The measurements of emulsion particles size were also carried out. The experiments showed the essential increase of phase immiscibility time with the pelobischofite contents increase. Some decrease in average particles size of standard emulsion was also registered. The emulsifiability of other magnesium containing preparations was at least twice worse. 

When comparable amounts of oil and water are mixed with surfactant a bicontinuous, isotropic phase is formed [6]. This bicontinuous phase, called a microemulsion, can coexist with oil- and water-rich phases [7,1]. The range of order in microemulsions is comparable to the typical length of the structure (domain size). When the strength of the surfactant (a length of the hydrocarbon chain, or a size of the polar head) and/or its concentration are large enough, the microemulsion undergoes a transition to ordered phases. One of them is the lamellar phase with a periodic stack of internal surfaces parallel to each other. In binary water-surfactant mixtures, or in... 

In this chapter we present various computational methods for studying the structure and stability regions of various phases within the basic and the extended LG models of the ternary surfactant mixtures. In particular we use ... 

A. Ciach. Statistical mechanics of ternary surfactant mixtures including microemulsions. Pol J Chem 66 1347-1387, 1992. 

K. Chen, C. Ebner, C. Jayaprakash, R. Pandit. Microemulsions in oil-water-surfactant mixtures Systematics of a lattice-gas model. Phys Rev A 55 6240, 1988. 

G. Gompper, S. Zschocke. Ginzburg-Landau theory of oil-water-surfactant mixtures. Phys Rev A 4d 4836-4851, 1992. 

A. Ciach, J. S. Hoye, G. Stell. Microscopic model for microemulsion. II. Behavior at low temperatures and critical point. J Chem Phys 90 1222-1228, 1989. A. Ciach. Phase diagram and structure of the bicontinuous phase in a three dimensional lattice model for oil-water-surfactant mixtures. J Chem Phys 95 1399-1408, 1992. 

The first two aspects entail relatively high concentrations of surfactants. In the last case, trace amounts are to be determined. When performing surfactant analysis, preconcentration and/or separation of the different surfactant classes are prerequisites for identifying and quantifying the compound in question. Furthermore, the trend is to analyze the individual components of any surfactant mixture. 

A numerical modeling of physical properties of a ternary surfactant mixture more typical of commercial products can be achieved on the basis of the parameter characteristics of the binary peripheral systems alone. 

FIG. 36 Synergistic mixture of alkane- (paraffin) sulfonates (PS) and fatty alcohol ether sulfates (FAES). Cleaning effect in miniplate test at 50°C, tap water (12° German hardness), 0.075 g of active surfactant mixture per liter. 

In some systems containing surfactant mixtures, a synergistic effect on the water solubilization capacity has been observed [50]. 

Different methods are used in microemulsion formation a low-energy emulsification method by dilution of an oil surfactant mixture with water and dilution of a water-surfactant mixture with oil and mixing all the components together in the final composition. These methods involve the spontaneous formation of microemulsions and the order of ingredient addition may determine the formation of the microemulsion. Such applications have been performed with lutein and lutein esters. ... 

High pressure homogenization may also be used to form microemulsions but the process of emulsification is generally inefficient (due to the dissipation of heat) and extremely limited as the water-oil-surfactant mixture may be highly viscous prior to microemulsion formation. ... 

Mixtures of aldehydes with surfactants are active in preventing corrosion, in particular in the presence of mineral or organic acids [646]. The aldehyde may be trans-cinnamaldehyde. The surfactant may be N-dodecylpyridinium bromide or the reaction product of trimethyl-1-heptanol with ethylene oxide [645]. Such aldehyde and surfactant mixtures provide greater and more reliable corrosion inhibition than the respective compositions containing aldehydes alone. 

A solution of a surfactant mixture in liquid paraffin, containing oil-soluble oxyethylated alkylphenol, having the formula with an Cg to C12 alkyl rest, the alkylphosphate of a higher fatty acid alcohol (RO)2PO — OH where R is Cio to C20, and a fatty acid amide of diethanolamine, are suitable for removing oils... 

Yang et al. [389] rapidly distinguished compounds extracted from paper, using on-line SFE-SFC-FHR in conjunction with principal component analysis. The quantitative determination of the surfactant mixture Triton X-100 and other complex oligoether surfactants by means of cSFC-FTIR flow-cells has been reported [390,391]. Practical applications of SFC-FTIR include the determination of nonvolatile compounds from microwave-susceptible packaging that may migrate into heated food. Another application is the analysis of fibre finishes on fibre/textile matrices. 

In cases where 2D NMR experiments are insufficient for a complete analysis of anionic surfactant mixtures, LC-NMR may provide better information. Characterisation of fatty alcohol ethoxylate (FAE) based oligomeric surfactants by on-line 2D (GCOSY, TOCSY and Homo 2DJ) stopped-flow HPLC- H NMR has been described [655,656]. The analysis of a typical mixture comprising three components (PEG and PEOs with different end-groups) is shown in Figure 7.34. In this representation, the 111 NMR frequency domain is in the... 

B Lundberg. Preparation of drug-carrier emulsions stabilized with phosphatidylcholine-surfactant mixtures. J Pharm Sci 83(1) 72—75, 1994. 

At the termination of the activity period, each participant s hands were held over a bowl and doused with 250 mL of a dilute dioctyl sodium sulfosucci-nate (anionic surfactant) mixture. This soap wash was followed by a 250-mL rinse with deionized water. The soap and water fractions were stored together in the same container. Fifteen grams of sodium chloride were added to the container to facilitate phase separation. The chlorpyrifos was partitioned with 200 mL of ethyl acetate, which was also used to rinse the bowl. The ethyl acetate extract was later analyzed for chlorpyrifos content. The amount of test substance removed was used to assess adult hand exposures and dose and also to assess the theoretical amount of test substance removed when children put their hands in their mouths. 

In this paper, we focused on behavior of industrial surfactant mixtures that can be used in calcic saline media, i.e. under conditions often encountered in onshore or offshore fields. The results obtained have been used for the laboratory testing and for interpreting the working mechanisms of a method of reducing losses of products in reservoir rocks and of propagating them more effectively in the formation to be treated. 

For the pseudo-binary mixture (a = 0.5) of sulfonate and nonylphenol with 30 E.O., figure 2 shows how the concentration of each of their monomer calculated by the RST theory (1), varies as a function of the overall surfactant concentration. It can be expected that the asymptotic regime in which monomer concentrations are stabilized will correspond to a plateau of the adsorption isotherm for the surfactant mixtures considered. 

Figure 1. CMC determination of surfactant mixtures. (Reproduced with permission from ref. 16. Copyright 1987 Deutsche Wissenschaftliche Gesellschaft.)...

The critical micellar concentrations of anionic/nonionic surfactant mixtures examined are low in a saline medium, so that, at the concentrations injected in practice, the chromatographic effects resulting from the respective adsorption of monomers are masked. Such surfactants propagate simultaneously in the medium in the form of mixed micelles. 

Graciaa A. et alii, The Partitioning of Nonionic and Anionic Surfactant Mixtures Between Oil/Microemulsion/Water Phases , n° SPE 13 030, Houston, 1984. 

Surfactant mixtures were used as obtained and are listed with their properties in Table II. Sodium chloride and calcium chloride were Fisher reagent grade. Deuterium oxide was Aldrich Gold Label and had a surface tension of 70.4 mN/m at 23°C measured with a W iI heImy pi ate tens i ometer. 

Haefliger, O.P. (2003). Universal two-dimensional HPLC technique for the chemical analysis of complex surfactant mixtures. Anal. Chem. 75, 371-378. 

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