Conformal solution corresponding-states

Necessarily chain conformations are reflected in solution properties such as viscosity. In a series of papers Utracki and his colleagues (8-11) have studied Newtonian viscosities of polymer solutions they have also studied polymer melts, and nonpoly-meric liquid phases, organic as well as inorganic ones. The aim of the work was to construct a corresponding states principle for viscosity n in function of temperature T and concentration c. 

The transport parameters for this model were evaluated using a corresponding state conformal solution procedure (Henderson and Leonard, 1971 Hanley, 1976) to predict the transport coefficient of fluids and mixtures. This is based upon the work of Ely and Hanley... 

Three-Parameter, Corresponding-States Conformal Solution Mixing Rules for Mixtures... 

The study presented herein has a number of implications. First, this study implies that it is possible to obtain accurate predictions of the thermodynamic behavior of mixtures within a multiparameter, corresponding-states framework using empirically determined exponents for the characterization parameters of the reference system in a first-order truncation of the conformal solution method expression for the Helmholtz free energy. This result is important to the continuing effort to develop a highly accurate multiparameter, corresponding-states framework for correlation of fluid properties, and to the industrial use of such a correlation. Second, this study demonstrates that there is a need to study separately rather than collectively (as herein) the errors introduced by the various major approximations introduced into the correlation meth-... 

Fig. 10. Cyclic voltammogram of horse cytochrome c at pH 9.30. Solution contained 0.35 mM oxidized cytochrome c in a medium consisting of 0.10 M sodium perchlorate, 0.02 M sodium borate and 0.01 M 4,4 -bipyridyl as promoter. An Au electrode, area 0.0079 cm was used. Scan rate 5mVs , temperature 25 °C. Two chemically non-reversible redox processes are observed. Wave 2c is associated with reduction of the State IV conformer which prevails at this pH. Note the virtual absence of wave Ic, which would be observed for reduction of the State III conformer. The corresponding return wave 2a is not observed because the Fe(II) product reverts immediately to the State IIj, conformer resembling State HI of the Feflll) form. Instead, re-oxidation (wave la) is observed at a potential appropriate for the native State III system. From Ref. 62, redrawn with kind permission of the authors...

The conformal solution or corresponding states correlation computes pseudo-reduced conditions for the mixture to conform to the reference substance. The reference substance may be a pure component or a mixture its properties can be given in tabular or equation format. 

As long as we retain only first order terms as in the theory of conformal solutions due to Longxtet-Higgins [1951] the treatment of critical phenomena is very simple. In this approximation the mixture obeys the theorem of corresponding states exactly as a single component. For example the compressibility factor at die critical point... 

This relation expresses the critical temperature of the mixture in terms of intermolecular forces and of the properties of a reference system which may be either the mixture treated in the approximation of the conformal solutions or any single component which satisfies the theorem of corresponding states. 

Fig. 3a and b. Fast exchange-slow exchange NMR transition for the conformational interconversion of octamethyltetrasiloxane. a, MAS 13C-NMR solid state spectra on the left side in comparison to solution spectra in propane-di on the right side (at 75.47 MHz), b. MAS 29Si-NMR spectra at 59.63 MHz. Temperatures are indicated in K, shift positions refer to TMS = 0 ppm and correspond to the scale at the bottom. (Ref. I0))... 

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