Activity coefficients in nearly athermal model polymer/solvent systems

Sheng, Yu Jane; Panagiotopoulos, Athanassios Z.; Tassios, Dimitrios P.

doi:10.1002/aic.690411014

Cited by 19 publications

(16 citation statements)

References 30 publications

(53 reference statements)

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“…24 SAFT and GFD give similar predictions in excellent agreement with simulation for ␥ 1 and in good agreement for ␥ 2 at low chain lengths ͑Fig. 9͒.…”

Section: Attractive Systemsupporting

confidence: 67%

“…In our previous study of engineering models, 24 we have shown that common models that incorporate a Flory-type expression, such as the popular UNIFAC equation 32 fail to reproduce the variation of activity coefficients with composition.…”

Section: Discussionmentioning

confidence: 99%

“…23 The description of the chain model and simulation details for the attractive systems can be found in previous work. 24 Results for all thermodynamic quantities are reported in reduced units, using the monomer energy and size parameters for scaling. For mixtures, component one always represents the solvent, and component two the polymer.…”

Section: Modelsmentioning

confidence: 99%

See 2 more Smart Citations

Mixing properties of model polymer/solvent systems

Sheng

Panagiotopoulos

Kumar

1995

The Journal of Chemical Physics

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Monte Carlo calculations have been performed on two nominally athermal polymer/solvent mixtures to test molecular theories of mixing properties for these systems. We first used the incremental chemical potential concept to derive an equation of state in the spirit of the generalized Flory dimer theory, without resorting to the concept of excluded volume. The resulting generalized Flory dimer-like theory and a related model, statistical associating fluid theory, were tested against simulation results for the excess volume, excess Gibbs free energy and component activity coefficients. Good agreement was obtained between the statistical associating fluid theory and computer simulations for all properties studied. The generalized Flory dimer theory, when applied self-consistently, was also able to provide quantitative predictions for the thermodynamic properties of these mixtures. An important result that emerges from our calculations is that these polymer solutions behave ideally when examined on the basis of a ''Flory-like'' reference state augmented by density effects. This asserts that the effects of molecular size disparity on system thermodynamics are properly captured by this approach. By contrast, the incompressible Flory approach fails to capture the dependence of activity coefficients on composition.

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“…24 SAFT and GFD give similar predictions in excellent agreement with simulation for ␥ 1 and in good agreement for ␥ 2 at low chain lengths ͑Fig. 9͒.…”

Section: Attractive Systemsupporting

confidence: 67%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Mixing properties of model polymer/solvent systems

Sheng

Panagiotopoulos

Kumar

1995

The Journal of Chemical Physics

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show abstract

“…The second modification (EFV-0.9) follows the suggestion of Sheng et al [18] that better representation of the combinatorial effects can be achieved by employing an exponent equal to 0.9 in the free-volume fractions…”

Section: Fv Related Models and Its Modified Treatment Descriptionmentioning

confidence: 97%

“…As such, a lot of modifications [12,17,18] were made to improve the predictions. Several modifications were focused on the FV fraction term considering that the model gave under-estimations for some systems.…”

Section: Fv Related Models and Its Modified Treatment Descriptionmentioning

confidence: 99%