Phase diagrams complex binary

The thermotropic behavior and phase diagrams of binary mixtures of copper and gold complexes of the type [MX(CNR)] (X = anionic ligand, R = p-alkoxyaryl group) have been studied [32] and the main results are ... 

So far we have considered only a single component. However, reservoir fluids contain a mixture of hundreds of components, which adds to the complexity of the phase behaviour. Now consider the impact of adding one component to the ethane, say n-heptane (C7H.,g). We are now discussing a binary (two component) mixture, and will concentrate on the pressure-temperature phase diagram. 

The example of a binary mixture is used to demonstrate the increased complexity of the phase diagram through the introduction of a second component in the system. Typical reservoir fluids contain hundreds of components, which makes the laboratory measurement or mathematical prediction of the phase behaviour more complex still. However, the principles established above will be useful in understanding the differences in phase behaviour for the main types of hydrocarbon identified. 

This work raises some interesting issues. The first is that the stoichiometry of a complex is not necessarily the most obvious. For example, it was reported initially that phthalic acid formed a 2 1 complex with alkoxystil-bazole [34], when in fact a careful study carried out by constructing a binary phase diagram (Fig. 11) revealed the complex to have a 1 1 ratio of the two components [35]. The reluctance of the system to form the more obvious 2 1 complex may relate to the presence of intramolecular hydrogen bonding or could even relate to the change in the pfCa of the second acid proton on com-plexation. 

Fig. 11 Binary phase diagram between phthalic acid and decyloxystilbazole. (Crc and Cra are the crystal phase of the complex and the acid, respectively E is the crystal smectic E phase). Adapted from [35]...

A few general and introductory remarks about these topics will follow, discussing the aspects of typical (binary and more complex) phase diagrams. 

All the phase diagrams reported above show a complete mutual solubility in the liquid state. The formation of a single phase in the liquid state corresponds to behaviour frequently observed in intermetallic (binary and complex) systems. Examples, however, of a degree of immiscibility in the liquid state are also found in selected intermetallic systems. Fig. 2.16 shows a few binary systems in which such immiscibility can be observed (existence of miscibility gaps in the liquid state). All the three... 

More complex situations were shown in Figs. 2.26 and 2.27, where some typical examples of isobarothermal sections of ternary alloy phase diagrams were presented. In the case of ternary systems, several binary and ternary stoichiometric (Fig. 2.28) phases and/or different types of variable composition phases (Fig. 2.29) may be found. We may differentiate between these phases by using terms such as point compounds (or point phases, that is, phases represented in the composition triangle, or more generally in the composition simplex by points), Tine phases , field phases , etc. 

Figure 5.11. Connected binary phase diagrams of the actinides. The binary phase diagrams (temperature vs. composition) for adjacent actinide metals are connected across the entire series (two-phase regions are in black, uncertain regions in grey). The transition from typical metallic behaviour at thorium to complex behaviour at plutonium and back to typical metallic behaviour past americium can be noticed (adapted from Hecker 2000).

The binary phase diagrams of the titanium oxides and sulphides are very complex with the formation of a very high number of intermediate phases (a similar behaviour is observed also for other intermediate transition metals such as vanadium). In the... 

Intermetallic chemistry of Be, Mg, Zn, Cd and Hg 5.12.4.1 Phase diagrams of the Be, Mg, Zn, Cd and Hg alloys. The systematics of the compound formation of these metals in their binary alloys with the different elements is summarized in Fig. 5.33. On the overall they give a rather complex picture even so a number of relationships and similarities between various pairs of metals may be singled out. To go into this point in more detail, in the same figure a comparison has also been made with the compound formation patterns of Ca and A1 which are described in 5.4 and 5.13 but are close in the Periodic Table to the metals here considered. The similarity between the Be and Zn patterns may be underlined, as also that between Be and Al, being an example of the so-called diagonal relationships presented in 4.2.2.2. 

It has already been noticed (see 3.9.4) that according to the mentioned concepts several ternary compounds may be considered as the result of a sort of structural interaction between binary compounds. As a consequence some regular trend could also be predicted for their occurrence in their phase diagrams and in the description (and perhaps modelling) of their thermodynamic properties. A few details about this type of structural relationships will be considered in the following and, in this introduction, examples of blocks of simple structural types and of their combination in more complex types will be described. 

Because there is an added term, the composition, binary systems are inherently more complex than unary systems. In order to completely represent the phase diagram of a binary system a three dimensional pressure-temperature-composition (P-T-x) diagram can be constructed. However, it is a more common... 

We can start, as did the ancient craftsmen, with the fusion of the iron oxide, FeO, with silica, SiO . The phase diagram for those binary mixtures show that whereas Si02 fuses at about 1713 C and FeO at 13 9 C, mixtures containing between 20 and 40 weight percent FeO fuse below 1250 C. Complexing with additions of another iron oxide, Fe203, in amounts of up to 10%, can lower the fusion temperature to about 1150 C. 

Matsuura, H., Fukuhara, K., Ikeda, K., Tachikake, M. (1989), Crystalline Complex of 18-Crown-6 with Water and a Phase Diagram of the Binary System as Studied by Raman Spectroscopy, Chem. Commun. 1814-1816. 

---