Three-Component Phase Diagrams

Figure 18 illustrates a model of the three component phase diagram of an IPN, where poljrmer I, poljrmer II, and monomer II are chosen for generality in expressing sequential IPN formation. On poljrmerizatlon of monomer II, first phase separation is initiated, probably by nucleation and growth. However, shortly a modified spinodal decomposition mechanism sets in as the overall composition is driven deeper into the phase separation region. 

Figure 18. Schematic three component phase diagram, showing the composition locus as monomer II polyermlzed [41].

Naturally, the results can be represented by a diagram similar to a three-component phase diagram, as shown in Fig. 5.10. Several interesting features are worth noting. First, when the m = 0 or state dominates, a large, positive enhancement is expected. The condition for a substantial enhancement is quite broad. For example, when the condition > 1.21 Di -i- 0.21D21 is satis-... 

A series of three solid solutions La2 x(Ba,Sr,Ca)xCu04 g was then prepared (152) the superconducting transition temperatures of the resulting products were determined from a.c. susceptibility measurements. The three-component phase diagram for this chemical system was plotted as a function of Tc. The maximum transition temperature of 37.0 K was observed for the composition, La18Sr0 2-Cu04 g, an end-member in the phase diagram. 

Figure 2-26 shows a typical three-component phase diagram.5... 

A common use of three-component phase diagrams is in analysis of miscible displacement. For instance, Figure 2-30 gives the phase envelope of an oil mixed with carbon dioxide.6 The oil is plotted as an artificial two-component mixture, with methane as one component and all other constituents added together as the other component. 

Ternary Diagrams — Three-Component Phase Diagrams —... 

A typical three-component phase diagram for the components used to prepare Loeb-Sourirajan membranes is shown in Figure 3.11. The comers of the... 

Figure 3.11 Schematic of the three-component phase diagram often used to rationalize the formation of water-precipitation phase separation membranes...

Figure 3.12 Membrane formation in water-precipitation membranes was first rationalized as a path through the three-component phase diagram from the initial polymer casting solution (A) to the final membrane (D) [24]...

Figure 3.13 The surface layer of water-precipitation membranes precipitates faster than the underlying substrate. The precipitation pathway is best represented by the movement of a line through the three-component phase diagram [27]...

FIGURE 4.25 Three-component phase diagram for the solubilization. Cre, Cremophor RH 40 Gly, glyceride Pol, poloxamer 124 L, isotropic microemulsion G, gel E, crude OAV emulsion E2, W/O emulsion. [Graph reconstructed from data by Kim et al. Pharm. Res., 18, 454 (2002).]... 

Figure 12.17. Three component phase diagram for TbCa40(B03)3, ScCa40(B03)3, and PrCa40(B03)3 with resulting luminescence indicated by the contours.

In the case of polystyrene blends with poly(vinyl methyl ether) two phase behaviour was found for blends from various chlorinated solvents whereas single phase behaviour was found for blends from toluene The phase separation of mixtures of these polymers in various solvents has been studied and the interaction parameters of the two polymers with the solvents measured by inverse gas chromatography It was found that those solvents which induced phase separation were those for which a large difference existed between the two separate polymer-solvent interaction parameters. This has been called the A% effect (where A% = X 2 Xi 3)-A two phase region exists within the polymer/polymer/solvent three component phase diagram as shown in Fig. 2. When a dilute solution at composition A is evaporated, phase separation takes place at B and when the system leaves the two phase region, at overall... 

In situ polymerisation does not however guarantee homogeneous blends as two phase regions can exist within the polymer/polymer/monomer three component phase diagram. In the case of vinyl chloride polymerisation with solution chlorinated polyethylene, the vinyl chloride has limited solubility in both poly(vinyl chloride) and chlorinated polyethylene. The phase diagram has the form shown in Fig. 3 The limit of swelling of vinyl chloride in the chlorinated polyethylene is A and the highest concentration of PVC prepared by a one-shot polymerisation is B. 

Fig. 3. The three component phase diagram for vinyl chloride, PVC and a chlorinated polyethylene is A and the highest concentration of PVC in a homogeneous blend prepared by a one-shot polymerisation is B...

Fig. 4. The three component phase diagram for mixtures of vinyl chloride, PVC and polyfbutyl acrylate). A polymerisation from E to F passes through the two phase region and an inhomogeneous blend results. A polymerisation from A to B, followed by reswelling with vinyl chloride to C and repolymerisation to D, avoids the two phase region and produces a homogeneous blend...

Solubility data are expressed as a solubility-concentration curve or as phase diagrams. The latter are preferable since a three-component phase diagram completely describes the effect of varying all three components of the system - namely, the soluhilisate, the solubiliser and the solvent. The axes of the phase diagram form an equilateral triangle (see Fig. 6.37), each side of which is divided into 100 parts to correspond to percentage composition. 

The sulfones, sulfolane and 3-methylsulfolane, are shown to function quite well, as cosurfactants with CTAB, in the solubilization of both organophosphorus esters and betahalosulfides. For the organophosphate used, tributylphosphate, it is shown through pseudo-three-component phase diagrams that the sulfone functions as effectively as the alcohol in its role of cosurfactant. Solubilization of chloroethyl ethyl sulfide is less effective when the sulfone cosurfactant is used, but is still a dramatic enhancement over its solubility in water alone. The effect of added salt on the solubilization is reported, as well as the effect of changes in the surfactant-cosurfactant ratio. Preliminary quasielastic lightscattering measurements are also reported for these unconventional systems. 

The experimental procedures described in this paper are mainly concentrated on the preparation of membranes from various polymer-solvent systems by precipitation in a nonsolvent, generally water. The membranes are then characterized in terms of their transport properties and structures. Furthermore, the three-component phase diagrams are determined for various polymer-solvent-precipitant systems. 

Determination of the Three-Component Phase Diagrams. The phase diagrams of four different polymer-solvent-precipitant mixtures were determined using the cloud point method and analysing the two phases obtained during the phase separation. The process is described in detail elsewhere (10). 

Figure 11. Three-component phase diagram at 25 C at the systems poly-amide-NMP-water, polyamide-DMAC-water, polyamide-DMSO-water, and cellulose acetate-acetone-water.

Figure 15.4 Schematic representation of three-component phase diagram.

Such a phase diagram is valid at one temperature. The effect of temperature on a three-component phase diagram can be visualized in three dimensions, with temperature on the elevation axis. The phase diagram looks like a triangular prism, with every horizontal slice corresponding to one temperature. 

In some cases a three-phase region occurs (Figure 3.5). The coexistence of three phases in equilibrium in an isothermal three-component phase diagram is... 

From the phase behavior of both binary mixtures (water-amphiphile and oil— amphiphile), it is now possible to account, at least qualitatively, for the three-component phase diagram as a function of temperature. The presence of a haze point on the oil-amphiphile phase diagram (critical point a) at temperature Ta shows that the surfactant is more compatible with the oil at high than at low temperature. The presence of a cloud point on the water-amphiphile phase diagram (the lower critical point (>) at temperature Tjj shows that (at least in the neighborhood of the temperature domain) the amphiphile is less compatible with water at high than at low temperature. As a consequence (the other parameters being kept constant), the amphiphile behavior depends on temperature. 

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