Solute‐induced effects on the structure and thermodynamics of infinitely dilute mixtures

Solvation effect on kinetic rate constant of reactions in supercritical solvents

“…As previously suggested (Chialvo and Cummings, 1994), since a locally denser region of solvent is observed even around a solvent molecule at any state condition, the focus in solvation should be on the difference between solvent structure around a solute molecule and solvent structure around a solvent molecule. Moreover, with the exception of the IS, for which the strength of the like and unlike intermolecular interactions are all identically the same (and therefore the corresponding solute-solute, solute-solvent, and solvent-solvent pair distribution functions will be also identical to one another, indicating that neither species shows preference for any other), the relative molecular asymmetry in the intermolecular interactions will translate into microstructural arrangements (solvation shells) with enrichment (depletion) of one component over the other with respect to what we would…”

“…The first case is trivial since YI:(ZS) = 5"' = p -' , and therefore (dP/d~~);,~,,~ = 0. For the two other cases, the virial theorem allows us to show that for an ideal gas solute in a real solvent (Hansen and McDonald, 1986), where we identify (Chialvo and Cummings, 1994) and consequently that in terms of the short-ram contributions to the partial molar volume of species u at intinite dilu,:on in the solvent. Thus, which highlights the effect of the species solvation contributions (Vr(SR)-?…”

“…To make contact with the microstructure of the system we express (dP/dx,)", p, xi in terms of total pair correlation function integrals (TPCFI), or alternatively, in terms of direct pair correlation function integrals (DPCFI) as follows (Chialvo and Cummings, 1994;Chialvo et al, 1996), so that, the short-range portion of the species partial molar volume at infinite dilution becomes Now, if the solvent becomes an ideal gas, that is, K + K '~ and p + ( P / k T ) , then Eqs. A14-A16 reduce to and The expressions Eqs.…”

Thermodynamic Aspects of Supercritical Fluids Processing: Applications of Polymers and Wastes Treatment

“…These experimental studies are based on the solubility of solids and on partial molar properties of dilute solutes in near-critical solvents [32,40,49,51,52] and also on spectroscopic techniques which provide information on solvation (short ranged interactions) and solvent structure [43,45,53,54,55,56,57,58,59].…”

“…Solutes with a same size but a different polarity present an equivalent factor E. Finally, E factor is very sensitive to the nature of the solvent and may vary to 8 orders of magnitude as a function of density [38]. The classical description takes into account short-range effects in relation to solvation phenomena, and long-range correlations due to local quasicriticality, that leads to large partial molar properties in the vicinity of the critical point [40,41,42,43].…”