Ternary mixed-salt solutions

Eqs. 2.76, 2.80, and 2.81 ignore volumetric ternary interaction terms (6>E, Yjk) that could P y important roles in mixed salt solutions (Monnin 1989 ... 

The solubility data of carbon dioxide in aqueous solutions of binary mixed salts obtained in this study are summarized in Table I those for ternary mixed salts are summarized in Tables II, III, and IV. Figures 1 and 2 show the solubility data for the potassium chloride-calcium chloride and sodium chloride-sodium sulfate-ammonium chloride mixed solutions, respectively, which are representative of all the data. The salting-out effect was shown in all the systems studied. 

The solubilities of carbon dioxide in aqueous solutions of seven binary and three ternary mixed salts chosen from eight kinds of electrolytes were measured at 25°C and 1 atm partial pressure of carbon dioxide by the saturation method. The experimental results were not correlated easily by the modified Setschenow equation, but they were correlated very well by the empirical two-parameter equation. The parameters in the equation for the binary and ternary solutions could be estimated by assuming an additive rule for the parameters of the component salt systems. This method, therefore, is useful for predicting the solubility of carbon dioxide in aqueous mixed-salt solutions. 

Diphasic liquid systems used in CCC may have a wide variety of polarities. The most polar systems are the ATPS made by two aqueous-liquid phases, one containing a polymer, for example, polyethylene glycol (PEG), the other one being a salt solution, for example, sodium hydrogen phosphate. The less polar systems do not contain water there can be two-solvent systems, such as heptane/acetonitrile or dimethylsulfoxide/hexane systems or mixtures of three or more solvents. Intermediate polarity systems are countless since any proportion of three or more solvents can be mixed. Ternary phase diagrams are used when three solvents are mixed together. 

It should be noted that the sol-gel process is particularly attractive for the synthesis of multicomponent particles with binary or ternary compositions using double alkoxides (two metals in one molecule) or mixed alkoxides (with mixed metaloxane bonds between two metals). Atomic homogeneity is not easily achieved by coprecipitating colloidal hydroxides from a mixture of salt solutions, since it is difficult to constmct double metaloxane bonds from metal salt. Hybrid... 

The phase behaviour of a mixed biopolymer solution is quantitatively characterized by a phase diagram, which graphically describes the boundary conditions of phase separation, the partitioning of the components between the phases and the effects of different variables (temperature, pH, salt concentration, etc.) on the phase behaviour of biopolymers. Conventionally, phase diagrams of three-component (ternary) systems are presented in triangular coordinates. However, an excess of solvent water... 

Figure 3 shows the plot for potassium chloride-calcium chloride binary salt system. Figure 4 shows the plot for sodium chloride-sodium sulfate-ammonium chloride ternary salt system. As shown in these figures, the plots of log(L0/L) vs. salt concentration all curve upward convexly, and the effects of these mixed salts on the solubility of carbon dioxide in the aqueous solutions do not show a direct correlation by the Setschenow Equation. These features are the same in all the mixed-salt systems considered here. 

Our results regarding the gas solubility in binary mixed solvents are presented in papers (3.1-3.2, 3.4). The new expression for the composition dependence of Hemy s constant in mixed solvents, which requires only the solubihties in the pure solvents (3.1), and the new analysis of the gas solubihty in aqueous salt solutions, which provides new criteria for salting-in or salting-out, should be noted (3.2). In addition, a method for predicting Henry s constant in multicomponent (ternary and higher) mixed solvents was developed and compared with experiment (3.5). Our method also aUows one to predict the solubility of a binary (or multicomponent) gas mixture in individual solvents (3.4). 

A solution of appropriate salts can also be reduced in the liquid phase by the addition of an appropriate reducing agent. Sodium borohydride has been used but care must be taken to remove the boron from the catalyst, particularly for the mixed noble metals. This has been accomplished by adding a dilute borohydride solution to the mixed metal salt solution under rapid agitation followed by a thorough washing of the precipitated metal black with warm water.The use of hydrazine, formaldehyde or formic acid is preferred to borohydride since the byproducts of the reduction do not contaminate the catalyst. Another procedure is to use a ternary alloy and to leach out one component as in the preparation of Raney nickel and similar catalysts. 

FIGURE 6 The effect ofan addition of NaCI in the binary water-gelatin and water-BSA system on the intensity-size distribution functions of the ternary water-gelatin (0.25 wt%)-BSA (0.25 wt%) system, obtained by mixing of the binary salt solutions of gelatin and BSA . 

With the use of thermodynamic relations and numerical procedure, the activity coefficients of the solutes in a ternary system are expressed as a function of binary data and the water activity of the ternary system. The isopiestic method was used to obtain water activity data. The systems KCl-H20-PEG-200 and KBr-H20-PEG-200 were measured. The activity coefficient of potassium chloride is higher in the mixed solvent than in pure water. The activity coefficient of potassium bromide is smaller and changes very little with the increasing nonelectrolyte concentration. PEG-200 is salted out from the system with KCl, but it is salted in in the system with KBr within a certain concentration range. 

The PEG/water, PPG/water, and PVAL/water are among the most extensively studied water-soluble polymer solutions. These systems typically show a closed-loop phase behavior (Figure 16.4). Results for some ternary systems have been reported many of these data are for PEG/Dextran/water and PEG/water/salts and related systems, which are important for separating biomolecules such as proteins. Only few data for PEG or other hydrogen bonding polymer with mixed water solvents have been reported. 

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