Critical solution temperature, binary ternary

In the phenomenological model of Kahlweit et al. [46], the behavior of a ternary oil-water-surfactant system can be described in terms of the miscibility gaps of the oil-surfactant and water-surfactant binary subsystems. Their locations are indicated by the upper critical solution temperature (UCST), of the oil-surfactant binary systems and the critical solution temperature of the water-surfactant binary systems. Nonionic surfactants in water normally have a lower critical solution temperature (LCST), Tp, for the temperature ranges encountered in surfactant phase studies. Ionic surfactants, on the other hand, have a UCST, T. Kahlweit and coworkers have shown that techniques for altering surfactant phase behavior can be described in terms of their ability to change the miscibility gaps. One may note an analogy between this analysis and the Winsor analysis in that both involve a comparison of oil - surfactant and water-surfactant interactions. 

Ternary liquid equilibria of systems including acids and esters with propane have also been studied (35, 75, 76), and phase diagrams of the type of Fig. 2.14 result. The data indicate that for any fatty acid-ester combination, a difference in the binary critical solution temperature with propane of less than 9.9°F. does not lead to selectivities sufficiently great to permit... 

Experimental results are presented for high pressure phase equilibria in the binary systems carbon dioxide - acetone and carbon dioxide - ethanol and the ternary system carbon dioxide - acetone - water at 313 and 333 K and pressures between 20 and 150 bar. A high pressure optical cell with external recirculation and sampling of all phases was used for the experimental measurements. The ternary system exhibits an extensive three-phase equilibrium region with an upper and lower critical solution pressure at both temperatures. A modified cubic equation of a state with a non-quadratic mixing rule was successfully used to model the experimental data. The phase equilibrium behavior of the system is favorable for extraction of acetone from dilute aqueous solutions using supercritical carbon dioxide. 

Two new structural groups of ternary superconductors (not ternary solid solutions of binary phases), noncubic at room temperature, have recently been reported. They are discussed briefly here because they are the first known chalcogenide phases exhibiting relatively high 7. The critical temperatures, however, are under 14°K. 

There is a large body of literature on phase diagrams for binary and ternary polymer solutions (Rory 1953 Tompa 1956 Cantow 1967 Utracki 1989) and extensive compilations of data (phase diagrams, cloud points, critical temperatures) for numerous systems (e.g., Wohlfarth 2004, 2008 Koningsveld et al. 2001). A few examples of such systems are listed in Table 2.21. 

Based on s discovery, a systematic and extensive experimental investigation of related ternary systems containing near-critical CO2 as the solvent and two heavier solutes has been carried out. The temperatures, pressures and compositions examined are within the range of conditions at which processes in super- and near-critical fluid technology applications take place. In ternary systems of the nature CO2 + 1-alkanol + alkane critical endpoint data were determined experimentally to characterize the three-phase behavior tig. To explain the observed fluid phase behavior, the binary classification of Van Konynenburg and Scott [5,6] was adapted to ternary systems, see section 2. 

Solid triangles, circles, diamonds, eight-pointed stars and squares are the binary nonvariant points (Z, and Q, N, p, L+M and R) in the subsystems A-B and A-C. It is accepted that temperatures of nonvariant binary points M and L are coincided. Open triangles, circles, diamonds, five-pointed stars, eight-pointed stars and squares are the ternary nonvariant points MQ, EfN, pR, NR, LN and pQ. Shaded circles and squares in binary systems are the metastable points N and R. Shaded circles and five-pointed stars are the metastable points NN and NR. Dashed fine is the monovariant curve Li = L2-G or Li = G-L2. Dash-dotted line is the monovariant curve Li = Lj-S or L = G-S. Solid line is the monovariant curve L1-L2-G-S. Double line is the coincided monovariant curves L1-L2-G-S and Li = Lj-S. Dotted line is the metastable part of critical curve Lj = Lj-G or Lj = G-L2. X is the relative amounts of the nonvolatile component in ternary solutions [X = Xb/(xbH-Xc)] (solvent-free concentration). 

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