In regular solution

Regular Solution Theory. The key assumption in regular-solution theory is that the excess entropy, is zero when mixing occurs at constant volume (3,18). This idea of a regular solution (26) leads to the equations ... 

We encountered the quantity AE ap/V in Eq. (8-35) it is the cohesive energy density. The square root of this quantity plays an important role in regular solution theory, and Hildebrand named it the solubility parameter, 8. 

In principle, linker groups are polymer-enlarged versions of blocking functions used in regular solution-phase chemistry. Therefore, enzymatic transformations that may be employed for the removal of protecting groups in solution, in principle may also open up alternative opportunities for releasing compounds from polymeric supports. The linkers developed so far can be divided into exo- and endo-linkers (Fig. 10.1) cleavable by exo- respectively endo-enzymes, as proposed by Flitsch et al. [6]. 

Unfractionated poly(a-phenylethyl isocyanide), [ ]tS°c = 0.41 dl/g, A n = 30000, also displays a similar decay in dichloroacetic acid at 30° C, where rjt of a 1.16% solution decreases from 1.515 to 1.165 in 5 days (19). This polymer, therefore, shows common properties in regular solutions, in which it has been... 

Hildebrand, J. H. Scott, R. L. in Regular Solutions, Prentice Hall Englewood Cliffs... 

The thermodynamics of non-ideal bulk mixtures has been considered in sec. 1.2.18. Non-idealities can be expressed in terms of activity coefficients, excess functions, pair interaction energies (as In Regular Solution theory) or through vlrlal expansions. For all these methods surface equivalents can be formulated. 

In the above considerations, the hydrophobic portions of both the membrane polymer and the small molecules that enter the membrane are expected to interact in the hydrophobic microphases in the membrane. It therefore becomes useful to find a numerical measure of the miscibility of these hydrophobic portions of molecules. In the case of complete molecules, both small and polymeric, the solubility parameter concept has been useful in the past. This concept is related to the enthalpy change which occurs on mixing in regular solution theory as developed by Hildebrand and coworkers (10) and as used for polymer solution theory by Flory (11). The Hildebrand solubility parameter is a measure of the attraction between molecules of the same kind, including dispersion forces, polar forces, and hydrogen bonding... 

Note In regular solution theory the solubility parameter has traditionally been given in the units shown. For this reason the traditional units, rather than SI units, appear in this table. 

Even though K depends only on temperature and pressure, it has an upper limit imposed by chemical stability that varies with composition. The minimum upper limit of K occms for an eqnimolar mixture where yi = y2 =. Hence, complete miscibility in regular solutions is consistent with K <2 (see Tester and Modell, 1997, p. 359). 

Examples of Liquid-Liquid Phase Separation in Regular Solutions, van Laar parameters at ambient pressure are provided in Table 29-1 for three binary mixtures that exhibit concentration-dependent miscibility. The corresponding graphs of Agmixing VS. Composition at constant T and p are provided in Figures 29-1 and 29-2. There is a range of compositions where... 

In regular solutions the activity coefficients depend on temperature and concentration but not on pressure. 

Activity Coefficients. The relationships between solvent solubility parameters and solvent activity coefficients y, can be obtained in regular solutions by the relationship... 

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