Phase Diagrams and Composition

Tolstoguzov, V.B. (2000) Compositions and phase diagrams for aqueous systems based on proteins and polysaccharides. International Review of Cytology, 192, 3-31. 

Tolstoguzov, V.B. (2000). Compositions and phase diagrams for aqueous systems based on proteins and polysaccharides. In H. Walter, D.E. Brooks, and P.A. Srere (Eds.), Micro-compartmentation and Phase Separation in Cytoplasm A Survey of Cell Biology. International Review of Cytology, Vol. 192. Academic Press, San Diego, pp. 3-31. 

Tolstoguzov, V. B. (2000). Composition and Phase Diagrams for Aqueous Systems Based on Proteins and Polysaccharides. Int. Rev. CytoL, 192, 3-31. 

Figures 4.9, 4.10 reveal how the equilibrimn compositions and phase diagrams can...

Table 14.1 Composition and phases for points in Fig. 14.2forthe K/P/Eu diagram. ...

Experimental and theoretical studies, as well as computer simulators, all require knowledge of the number and compositions of the conjugate phases, and how these change with temperature, pressure, and/or overall (k ., system) composition. In short, all forms of enhanced oil recovery that use amphiphiles require a detailed knowledge of phase behavior and phase diagrams. 

This is a rather useful computer program that allows the user to make several types of calculations, including reaction enthalpies, heat balances, equilibrium compositions, and phase stability diagrams. The noncritically evaluated database contains more than 11,000 compounds. Updated versions are now available. 

H T2 relaxation experiments have moreover been used to investigate the phase composition, interfaces and phase diagrams of polymer solutions, emulsions and coreshell lattices [167-173]. 

Optimum thickness. At fixed composition a phase diagram of the catalyst layer can be generated, which establishes a relation between the optimum thickness interval of the catalyst layer and the target current density jo (or jo interval) of fuel cell operation. The optimum compromise between kinetic losses and mass transport losses is realized in the intermediate regime. The existence of an upper limit on the thickness beyond which the performance would start to deteriorate is due to the concerted impact of oxygen and proton transport limitations, whereas considered separately each of the effects would only serve to define a minimal thickness. 

Fig. 9. Temperature-composition isobaric phase diagram for the fully hydrated dipal-mitoylphosphatidylcholine/dipalmitoyl-phosphatidylethanolamine system constructed using the temperature gradient method. The notation used is that of Luzzati [8] and is as follows Lc, lamellar crystalline (also referred to as the subgel phase) L f, lamellar gel phase with hydrocarbon chains tilted with respect to the bilayer normal P)el, ripple phase L. lamellar liquid crystal phase. Insert bold line in graph as indicated...

The subject matter is introduced by a short exposition of the Gibbs phase rule in Sec. 8.2. Unary component systems are discussed in Sec. 8.3. Binary and ternary systems are addressed in Secs. 8.4 and 8.5, respectively. Sec. 8.6 makes the connection between free energy, temperature, and composition, on one hand, and phase diagrams, on the other. 

The objective of this section is much less ambitious and can be formulated as follows If the free-energy function for all phases in a given system were known as a function of temperature and composition, how could one construct the corresponding phase diagram In other words, what is the relationship between free energies and phase diagrams Two examples are considered below polymorphic transformation in unary systems and complete solid solubility. 

Sophiea et al. published the first classical composition-temperature phase diagram, working with the semi-IPN net-polyurethane-mter-poly(vinyl chloride) [Sophiea et al., 1994b]. They found a lower critical solution temperature, LCST = 120°C below this temperature the system was one-phased, and above, two-phased. Such behavior is now known to be characteristic of most polymer blends (see Chapter 2). 

As reviewed above, the miscibility of the HDPE/LLDPE blends seems to depend on the molecular weight, polydispersity, composition, and temperature, as well as on the branch content and length of the components. However, the HOPE and LLDPE samples used in the blend studies were limited to certain ranges of molecular weight, polydispersity, and branch content. Further, there was a distinct lack of information regarding the phase diagram. Therefore, more quantitative analysis is still needed in order to completely understand the miscibilities and phase diagrams of HOPE/ LLDPE blends. 

Differential thermal analysis is the monitoring of the difference in temperature between a sample and a reference compound as a function of temperature. These data can be used to study heats of reaction, kinetics, phase transitions, thermal stabilities, sample composition and purity, critical points, and phase diagrams. 

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