71-co-AN), such as the glass transition temperature, Tg; the sorption enthalpy, IH 1S, sorption free energy, IG 1S; sorption entropy, IS 1S; the weight fraction activity coefficients, a| 1a; partial molar free energy of mixing, IG 1a; partial molar heat of mixing, IH 1a; and the Flory-Huggins interaction parameters, I 12a, at infinite dilution.
The weight fraction activity coefficient, a|1, of the solute probe at infinite dilution was calculated according to the following equation :
The authors highlight that activity coefficients of mixtures are higher if the solute is gas ethane, except for the n-hexane-ethane system.
In this article, we use a quick and convenient way of predicting fugacity and activity coefficients of some systems, previously reported in literature.
As a consequence, the sorption parameters and the solvent activity coefficients
and the Flory Huggins parameters were calculated only in the temperature range from 60 to 80[degrees]C and for polar-type and dispersion-type solvents in whose retention diagrams this decreasing linear zone can be clearly observed.
Group contribution estimation of activity coefficients
in nonideal liquid mixtures.
The modified Clegg-Pitzer equations have been used to derive the activity coefficients
of different species present in the equilibrated liquid phase (Li and Mather, 1994; Kundu et al.
The mean activity coefficients
calculated by eq (1) from these smoothed values of E and the values of E[degrees] given in table 1 are summarized in table 3.
Table-6: The weight fraction activity coefficients
From these possible models), (the NRTL model is selected), (because the extension of NRTL model--the polymer NRTL model--includes the effect of polymer properties on the activity coefficients
of the components.
The weight fraction activity coefficient
(O1 ) of the solute at infinite dilution can be calculated from following relation .
These methods attempt to characterize polymer-solvent interactions by using activity coefficients
, acid-base parameters , interaction parameters , polarity indices , and others.