Quaternary systems

Fig. 5. Lower and upper critical tielines in a quaternary system at different temperatures and a plot of the critical end point salinities vs temperature, illustrating lower critical endline, upper critical endline, optimal line, and tricritical poiat for four-dimensional amphiphile—oil—water—electrolyte-temperature...

These multicomponent calculations are now computerized, and complicated systems, such as tire Si-C-H-Cl quaternaty, may be solved by the use of commercially available software, e. g. the IVTAN database. The solution to this multicomponent system which is obtained by this means is somewhat subjective, since, at the time of writing for example, data are available for 72 gaseous species in the quaternary system Si-C-H-Cl. Choosing 19 of the most probable of tlrese, and using tire IVTAN software to solve this multicomponent equilibrium, yields the following results for tire most probable species (see Table 3.2). 

Vierseit, n. quadrilateral, vier-seitig, a. four-aided, quadrilateral (specif., square), -stellig, a. four-place. VierstofFsystem, n. quaternary system, vierstufig, a. four-stage. 

Induction of asymmetry into the /J-lactam-forming process was inefficient with acyclic imines having chiral groups on the nitrogen [19] but efficient with rigid, cyclic chiral imines (Table 3). One of these was used as a chiral template to produce highly functionalized quaternary systems (Eq. 5) [34]. 

Fig. 8.15 Concentration simplex of the La-B-C-N system. Combinations include one quaternary system, four ternary systems, and six binary systems.

Snee, T.J., Barcons, C., Hernandez, H., and Zaldivar, J.M., 1992, J. Thermal Analysis, 38, 2729. Sdrensen, J.M. and Arit, W.. 1980, Liquid-Liquid Equilibria Data Collection. Vol. V. Part 3 Ternary and Quaternary Systems , DECHEMA Chemistry Data, Dechema, Frankfurt. 

The second major component of the education of a modern materials chemist in materials synthesis is, of course, in phase equilibria, possibly through the treatment of quaternary systems and P—T—X (pressure—temperature—composition) equilibria. This subject was essentially eliminated from chemistry departments and is taught in the materials and geological science departments. Every student (and professor) aspiring to be a materials chemist will have to master this subject. 

Figure 4.20 Tetrahedron space model for the phase diagram of the quaternary system A-B-C-D. The isotherms T], 72, T3 are shown for the primary phase volume of component A [17]. Reprinted with permission of The American Ceramic Society, www.ceramics.org. Copyright [1984]. All rights reserved.

B. System NH -C0 -H S-H >0 This quaternary system is dealt combining the equations and assumptions used to describe the ternary systems NH3-CO2-H2O and NH3-H2S-H2O. In the mass balances for the liquid phase molecular CO2 and H2S are neglected. At given temperature and total liquid molalities there are eleven unknown... 

The correlation has also been applied to a wide variety of ternary and quarternary systems by Vega and Funk (1 9). Again, the correlation is very good for the concentrated region and was effective in describing complex equilibria occuring in the quaternary system of NaCI-NaNOg-NapSO.-hLO. 

The low interfacial tensions between two liquids have been measured for different systems by using the pendant drop method. In the case of the quaternary system Ci2ll25S 3 tNa+H20+n-Butanol+Toluene, the interfacial data as measured by pendant drop method are compared with reported literature data, using other methods (with varying NaCl concentration). In order to understand the role of co-surfactant, ternary systems were also investigated. The pendant drop method was also used for measuring the interfacial tension between surfactant-H20/n-alcohol (with number of carbon atoms in alcohol varying from 4-10). The interfacial tension variation was dependent on both the surfactant and alcohol. 

All chemicals used were of very high purity grade (>99 %). The quaternary systems were mixed and allowed to reach equilibrium over a week at constant temperature, with occasional stirring. The oil phase (top phase) was placed in the measuring cell of the pendant drop apparatus. The bottom (aqueous) phase was filled in the syringe for the measurement. 

These studies, carried out by measuring interfacial tensions, Yq , between aqueous and oil phases, by using the pendant drop method, show that this method is very useful for ternary and quaternary systems. In one system (A), NaDDS + H2O + n-butanol + Toluene... 

Kurihara, K., Takimoto, Y., Ochi, K., and Kojima, K. Vapor-liquid equilibrium data for the quaternary system acetone + chloroform-t methanol -t benzene at 101.3 kPa, J. Chem. Eng. Data, 45(5) 792-795, 2000. 

The general absorption pattern of quaternary pavines strongly resembles that of the tertiary analogs with the exception of the expected downfield shifts for each of the protons. In particular, the bridgehead protons will move downfield by about 1-1.5 ppm (32,35). N,N-Dimethyl protons will be observed as a singlet between 8 3.3 and 3.7 (29,32,35). The set of empirical rules deduced for aromatic proton chemical shifts in a tertiary system has been shown to apply also to the quaternary system (29). A listing of aromatic proton chemical shifts of some quaternary pavine bases has been presented as a reference for future studies on similar compounds (29). 

Values of a diffusion coefficient matrix, in principle, can be determined from multicomponent diffusion experiments. For ternary systems, the diffusivity matrix is 2 by 2, and there are four values to be determined for a matrix at each composition. For quaternary systems, there are nine unknowns to be determined. For natural silicate melts with many components, there are many unknowns to be determined from experimental data by fitting experimental diffusion profiles. When there are so many unknowns, the fitting of experimental concentration... 

The relationships derived by F W appear to be substantiated by previously reported data on the effects of particle size and relative amounts of ingredients for the binary systems Mg-LiNO3, Mg-NaNOj, Mg-KNOj the quaternary systems Mg-NaNC>3-Laminac-PVC and the 5 components systems of Mg-BafNOj -KClO -Laminac-PVC... 

Synthesis of zeolites in mixed alkali-TMA systems is extended to quaternary cation systems in zeolites described in a patent by Kouwen-hoven and Cole (17). These zeolites, designed KSO-2-6, are synthesized from ternary and quaternary systems of TMA and Na, and a third or fourth cation consisting of K or Li, or both. They have pore volumes in the region of 0.12-0.15 cm3/gram and stated pore sizes from 5 to 7 A. All appear to be related to previously known structure types. 

---