Loading...

Study of phase behaviour for the aqueous two-phase polymer - polymer systems using the modified UNIQUAC-NRF model

Pazuki, G. R ; Sharif University of Technology | 2009

780 Viewed
  1. Type of Document: Article
  2. DOI: 10.1080/00319100701594370
  3. Publisher: 2009
  4. Abstract:
  5. A modified form of the UNIQUAC-NRF activity coefficient model was used to study the phase behaviour of the aqueous two-phase systems (ATPSs) of polyethylene glycol (PEG) and dextran (DEX) with different molecular weights at various temperatures. In the proposed model, a ternary interaction parameter was added to the expression for the excess Gibbs free energy and, in turn, to the corresponding activity coefficient rendered by the UNIQUAC-NRF model. The combinatorial part of the new model takes the same form as that of the original UNIQUAC model and the residual part considers the nonrandomness and also the binary and the ternary interactions among the molecules in mixtures of PEG, DEX, and water. The results show that the new model can more accurately correlate the experimental data for the systems studied in this work than those obtained from the original UNIQUAC and the UNIQUAC-NRF activity coefficient models. In order to favourably compare the results the same minimisation procedure and the same experimental data were used for the models studied in this work. The results for the Root Mean Square Deviations (RMSD) produced by the three UNIQUAC-based models are also reported
  6. Keywords:
  7. Activity coefficient ; Activity coefficient model ; Aqueous two phase ; Aqueous two-phase system ; Excess Gibbs free energy ; Experimental data ; New model ; Non-randomness ; NRF model ; Phase behaviour ; Polymer systems ; Root mean square deviations ; Ternary interaction parameter ; Ternary interactions ; UNIQUAC ; UNIQUAC models ; UNIQUAC-NRF model ; Activity coefficients ; Binary mixtures ; Drug products ; Ethylene glycol ; Glucose ; Phase equilibria ; Polyethylene glycols ; Polyethylene oxides ; Mathematical models
  8. Source: Physics and Chemistry of Liquids ; Volume 47, Issue 2 , 2009 , Pages 148-159 ; 00319104 (ISSN)
  9. URL: https://www.tandfonline.com/doi/abs/10.1080/00319100701594370