Pseudoternary system water

FIGURE 21.8 Phase diagram in the pseudoternary system water/SDS hexanol (1 1.76)/dodecane. Emulsification paths for the preparation of nano-emulsions at a final water content of 98 wt%. 

Figure 14.8 Pseudoternary phase diagram at 25 °C of the system water-C 2 04-hexadecane.

Most of the ternary or pseudoternary systems used in extraction are of two types one binary pair has limited miscibility (termed a type I system), or two binary pairs have limited miscibility (a type II system). The water + acetic acid + methyl isobutyl ketone (MIBK) system... 

Fig. 37.11 Pseudoternary phase diagram of the system water - - dodecane -I- polyoxyethylene-(7)-lauryl ether -1-decanol, where the dodecane fraction is maintained at a constant 40% (v/v), for which reason the scales run from zero to 60% instead of 100% of a full diagram. The areas labelled 1, 2 and 3 delineate the domain of the oil-continuous isotropic microemulsion at 20, 25 and 35°C, respectively. Redrawn from Ziegenmeyer and Fuhrer.2 ...

Solubilization, Microemulsions and Emulsions. - Micellar solutions with both normal (Li) and reverse (L2) curvature, e.g. o/w and w/o type systems, can be swollen by oil and water to obtain water/oil/amphiphile ternary or pseudoternary systems. These systems have been widely used as solubilizing media for structural investigations of the immobilized solubilizate (a protein for instance), for drug delivery systems, and also for reaction media, (micellar catalysis). Ternary systems based on water, oil, and amphiphile mixtures can form a variety of Li and L2 monophasic regions. When these systems form isotropic solutions spontaneously, they are termed microemulsions. The formation of a microemulsion is related mainly to a substantial decrease of the interfacial tension (Yo/w) at the oil-water interface, due to the amphiphilic molecules located at the polar-apolar interface. This occurs in agreement with the typical equation ... 

FIGURE 10.9 Pseudoternary phase diagram of the system water/TW40/IMW/IPM at 25°C, where the weight ratio of TW40 to IMW was fixed at 1 1. The compositions of the microemuisions used in the drug release study are denoted. 

Alany, R. G, Davies, N. M., Tucker, I. G, and Rades, T. (2001), Characterising colloidal structures of pseudoternary phase diagrams formed by oil/water/amphiphile systems, Drug Dev. Ind. Pharm., 27(1), 33-41. 

Figure 4. Pseudoternary diagram of oil-water-surfactant system with three compositions of interest. (Reproduced with permission from reference 40. Copyright 1977 Academic Press.)...

Pseudoternary phase diagrams of the water-dodecane-SDS-pentanol and water-dodecane-SDS-hexanol systems have been investigated in detail. A great variety of new domains has been evidenced in the oil rich part of these diagrams including, one-, two-, three- and four-phase liquid regions. An interpretation of these diagrams is proposed it is shown that interactions between water domains play an important role in microemulsion stability. 

Figure 2. W/S pseudoternary diagrams at T = 21,5°C (in volume) of the water-dodecane-SDS-hexanol system.

Figure 3. W/S pseudoternary diagrams at T = 21.5 °C ( in volume) of the water-dodecane-SDS-pentanol system. Top W/S = 1 bottom W/S = 1.4. L, Lg, and L designate respectively an isotropic phase, a birefringent phase and a flow birefringent liquid phase.

The demixing curves in the W/S pseudoternary diagrams for the hexanol and pentanol systems have been calculated according to the above theoretical treatment. These lines have been determined in the following way. The calculation of the state equation is applied to a dilution line along such a line the inverse micelles have a constant radius R. The micelles contain the whole water (volume Vw), the surfactant (volume V ) and a part of the alcohol V. The rest of alcohol is in the oil continuous phase. We suppose that the alcohol-oil ratio in the continuous phase is constant and is equal to k. Besides, in the calculation of the micellar radius R one assumes that the surfactant and the alcohol molecules which are situated at the interface have a constant area per chain s. In mos of the previous studies s has been found constant and equal to 25 A2. This value is taken equal for the alcohol and surfactant chains. Consequently ... 

Figure 8.6 Pseudoternary phase diagram of a system containing 20 wt.% emulsifier (Cs/io-APG, Q2/14-APG and GMO), 20 wt.% perfume oil, 0.6 wt.% oil (dicapryl ether, octyldodecanol) and 59.4 wt.% water at 25°C. The formation of microemulsions was studied as a function of the emulsifier s composition. The dotted lines separate the o/w- from the w/o-region. ME indicates a one-phase microemulsion. (From Ref. [39], reprinted with permission of Elsevier.)...

FIGURE 6.21 Schematic pseudoternary diagram of nonionic surfactant water-n-hexade-cane-oleyl alcohol system showing the change in oil drop composition with time. Reprinted with permission from Lim and Miller (1991a). Copyright 1991 American Chemical Society. 

R. Aboofazeli, N. Patel, M. Thomas, and M. J. Lawrence 1995 Investigations into the formation and characterization of phospholipids microemulsions. 4. Pseudoternary phase diagrams of systems containing water-lecithin-alcohol and oil—the influence of oil. Int. J. Pharm. 125,107-116. 

FIGURE 14.8 Pseudoternary phase diagram of a water-benzyl chloride-surfactant-plus-cosurfactant system for on-site decontamination. (Reproduced from Gonzaga, R, Perez, E., Rico-Lattes, I., and Lattes, A., New J. Chem., 25, 151, 2001. With permission.)... 

FIG. 28 Pseudoternary phase triangle of a six-component system (60% water, 25 °C). 

The effect of microemulsion structure on reaction rate has also been studied in relation to oxidation and reduction of cysteine residues in keratin [10]. The system sodium dodecyl sulfate (SDS)/n-pentanol/water/dodecane was chosen as a microemulsion because in this system the realm of the existence of the isotropic region in the pseudoternary phase diagram is a continuous domain, extending from the water apex to the close vicinity of the hydrocarbon-surfactant edge. It was shown experimentally that the microemulsion structure varied smoothly with composition within the isotropic region. 

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