Polar + nonpolar mixtures, thermodynamic

Rathbun and Babb [20] suggested that Darkens equation could be improved by raising the thermodynamic correction factor PA to a power, n, less than unity. They looked at systems exhibiting negative deviations from Raoult s law and found n = 0.3. Furthermore, for polar-nonpolar mixtures, they found n = 0.6. In a separate study, Siddiqi and Lucas [22] followed those suggestions and found an average absolute error of 3.3 percent for nonpolar-nonpolar mixtures, 11.0 percent for polar-nonpolar mixtures, and 14.6 percent for polar-polar mixtures. Siddiqi, Krahn, and Lucas (ibid.) examined a few other mixtures and... 

C02 Binaries. The final group of binaries that will be examined is that of C02 with nonpolar and polar compounds. The thermodynamic properties of C02 differ significantly from those of similar nonpolar compounds, and this is the result of its very strong quadrupole moment. This effect is seen more clearly in the behavior of C02 in mixtures. King and his students have reported By data for several C02 binaries the resulting ky s have been in Table V. 

The problems associated with new synthesis gas processes are far greater than problems associated with gas processing plants or refineries because of water, salt, sludge, ammonia, and cresols present in the process streams. This paper attempts to identify the magnitude of the problems and methods for solving these problems. The problem of predicting the thermodynamic properties of nonpolar-polar mixtures by means of equations of state is also identified as an area needing study. 

In Chapter 4, methods based on equations of state were presented for predicting thermodynamic properties of vapor and liquid mixtures. Alternatively, as developed in this chapter, predictions of liquid properties can be based on correlations for liquid-phase activity coefficients. Regular solution theory, which can be applied to mixtures of nonpolar compounds using only properties of the pure components, is the first type of correlation presented. This presentation is followed by a discussion of several correlations that can be applied to mixtures containing polar compounds, provided that experimental data are available to determine the binary interaction parameters contained in the correlations. If not, group-contribution methods, which have recently undergone extensive development, can be used to make estimates. All the correlations discussed can be applied to predict vapor-liquid phase equilibria and some, as discussed in the final section of this chapter, can estimate liquid-liquid equilibria. 

Reverse micelle systems (or water-in-oil microemulsions) are used as microreactors to synthesize ultrafine particles with a narrow particle size distribution by controlling the growth process [90]. Reverse micelles are nanometer-scale surfactant associated in colloid shaped structures formed in a nonpolar organic solvent. Polar solvents such as water are easily soluble inside reverse micelle because the inside of the reverse micelles is quite hydrophihc. Reverse micelle systems are thermodynamically stable, isotropic, transparent mixtures of oil and water separated by a thin... 

Initial works on the phase equilibrium of polymer solutions were concerned with nonpolar solutions using carefully prepared quasi-monodisperse polymer fractions [78]. The theory and practice was later extended to molecularly heterogeneous polymers [84], multicomponent solutions (ternary mixtures) such as polymer/solvent mixture [16, 85] and polymer mixture/solvent [86], and polymer blends [79, 80], among others [87]. Improvements on predicting thermodynamic properties were particularly proposed for polymer solutions of industrial importance, including those having polar and hydrogen-bonded components [16]. 

Microemultions represent an important subject of self-organizing amphiphilic systems. They are thermodynamically stable, macroscopically homogeneous mixtures of at least three components polar and nonpolar liquid phases (usually water and oil) and a surfactant that, on a microscopic level, forms a film separating the two incompatible liquids into two subphases. The microemusions form well-organized local structures like simple surfactant-water (or oil) binary systems. The distinctive feature of microemulsions, compared to micellar systems, is the presence of significant amounts of oil in the system. Also, the constraint of a maximum thickness for the hydrophobic medium in micellar systems is removed, since the hydrophobic region is now swollen with oil [108]. 

From R. Nakamura, G.J.F. Breedveld, J.M. Prausnitz, "Thermodynamic Properties of Gas Mixtures Containing Common Polar and Nonpolar Components", Ind. Eng. Chem. Process Des. Dev., vl5, 4, pp557-564 (1976)... 

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