Phase temperature-concentration diagram

Gels are obtained for concentrations shown in the temperature-concentration phase diagram (Figure 1). Electron spin resonance (ESR) shows (10) that for a given temperature only a fraction (p) of the initial steroid concentration is transferred from the solution to the gel network. The picture of this gel is thus of a supersaturation gel there is a dynamic equilibrium between free molecules in solution and aggregated steroid molecules included in the long objects which constitute the gel network. The free steroid molecules concentration at a temperature where the gel state is stable is (1-p), while C p is the steroid concentration within the solid-iike gel aggregates. 

Fig. 6. Temperature-concentration phase diagrams for four PHIC-toluene systems with different molecular weights [64]...

Here, rheology is used to characterize the gel state, whose stability, as measured thermodynamically or kinetically, can be described by temperature-concentration phase diagrams or simply time. The structural features of gelator aggregates at nanoscopic scales are described via data from the complementary techniques of electron microscopy and scattering techniques. Finally, the optical properties, including absorption and luminescence, are detailed. 

Figure 11.5 The temperature-concentration phase diagram for aqueous j crystallin (MW 20 000) systems (pH = 7, /= 0.24 mol kg" ) , cloud point measurements , concentration measurements of separated phases A = critical point.

Figure 1 Temperature concentration phase diagram of aqueous solutions of methylcellulose A4C,M sol-gel transition, , O binodal curve, (i) solution, (ii) turbid gel, (iii, iv) clear gel, shaded region occurrence of the phase separation after one month...

Figure 4.7a shows the temperature-concentration phase diagram for the system naphthalene-/ -naphthol, which forms a continuous series of solid solutions. The melting points of pure naphthalene and -naphthol are 80 and 120 °C, respectively. The upper curve is the liquidus or freezing point curve, the lower the solidus or melting point curve. Any system represented by a point above the liquidus is completely molten, and any point below the solidus represents a completely solidified mass. A point within the area enclosed by the liquidus and solidus curves indicates an equilibrium mixture of liquid and solid solution. Point X, for instance, denotes a liquid of composition L in equilibrium with a solid solution of composition S, and point Y a liquid F in equilibrium with a solid S. ... 

Fig. 9. Temperature-concentration phase diagram of PVC-diethyl ma -onate gels aged for 24 h at 20 °C (O) temperatures determined from the first heating by DSC (scan speed 20°C/min bars indicate the width of the melting endotherm) and ( ) melting temperatures determined visually by the ball-drop method (heating rate 2°C/min). Eeproduced from Macromolecules [Ref. 106] by the courtesy of the authors and The American Chemical Society...

Figure 3. (a) Temperature-concentration phase diagram at P =0.15 and 0.20, for LJ polymer solutions, (b) Pressure-Temperature phase diagram predicted by coil-to-globule transition of a single chain (lines) compared to LCSTs from phase behavior simulations (points). Ref. [61]. 

Rg. 10.26 (a) Temperature-concentration phase diagram of a polymer solution forming networks by double... 

Figure 3.4 The temperature-concentration phase diagrams of BPS-m (m=5,10,20, and 30) with BmimPFj. The phase abbreviations are as follows micellar phase (1 ), discontinuous cubic liquid crystal phase (1 ), hexagonal liquid crystal phase (H ), lamellar liquid crystal phase (L ), lamellar gel phase (L ), reverse micellar phase (L ), ionic liquid phase (IL), and two-phase separation (II). The chemical structure of j0-sitosterol ethoxylates as a typical example of BPS-m is also shown in this figure. Reproduced from Sakai et al. [37] with permission from Japan Oil Chemists Society.

Perhaps the earliest example of this is the temperature-concentration phase diagram where FeC alloys show a fee phase both above and below a bcc phase. J. Billard, personal communication. 

Figure 4.18 Temperature-concentration phase diagram for sPS/ diphenyl methane. C, and Cj stand for molecular compounds of differing stoichiometry and for solid phases (the former crystallized solvent, the latter to the form of sPS). is the form evidenced...

Figure 3.4 Temperature-concentration phase diagram for polystyrene-acetone [43]...

Eutectic point (Tc) A single point on a temperature concentration phase (or state) diagram for a binary solution (e.g., water and sugars or salts) where the solution can exist in equilibrium with both crystalline solute and crystalline solvent. Under equilibrium conditions, cooling at Te results in simultaneous crystallization of solvent and solute in constant proportion and at constant temperature until maximum solidification has occurred (based on Fennema, 1996). 

Fig. 3. Schematic diagrams a surface tension versus concentration of a surfactant, b phase diagram of a surfactant near the Krafft temperature, c phase diagram of 3-0-dodecyl-D-glucitol [11]...

A temperature-composition phase diagram for a surfactant solution is a characteristic phase diagrarr that delineates the conditions under which crystalline surfactant, monomers, or micelles will exist. On the phase diagram shown in Figure 12.5 (Smirnova, 1995), L represents the liquid phase, S the solid phase, and )(the surfactant mole fraction. The critical micellar temperature, CMT, is deLned as the line between the crystalline and micellar phases. Micelle formation occurs at temperatures greater than the CMT. The critical micellar concentration, CMC, line separates the micellar and... 

Many solutes do not crystallize from a freeze-concentrated aqueous solution. Modification of the temperature/composition phase diagram to illustrate this behavior was first suggested by MacKenzie (15) and termed a supplemented phase diagram, whereas other investigators have used the term... 

The plots of free energies of different temperatures. The phase diagram has been constructed by intersection points of these plots and with the use of method of total tangent lines to them. This diagram defines the temperature and concentration regions of forming of all phases of chemical reaction. 

Figure 5. Temperature versus concentration phase diagram for aqueous HPC-E and HPC-L solutions.

Fig. 5 The temperature-polymer concentration phase diagrams of PEO-PPO-PEO copolymer EO13PO30EO13 aqueous solutions at the absence and presence of a-CD with different a-CD concentrations [70]...

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