Modeling Process Partitioning of Biomolecules in Polymer-Polymer and Polymer-Salt Aqueous Two-Phase Systems (ATPS) using an Extended Excess Gibbs Energy Model

A new local composition model was used to study the phase behavior of polymer-polymer and polymer-salt aqueous two-phase systems. The proposed model has three terms which account for the combinatorial, the long-range and the short-range effects in solution. The Flory-Huggins and the Debye-Huckel models were used for the combinatorial and long-range contributions. The interaction parameters of the model studied in this work can be regressed using a non-liner regression between the experimental data and those obtained from the proposed model. Also, this model was applied for modeling the partitioning of biomolecules in polymer-polymer and polymer-salt aqueous two-phase systems. The results showed that the proposed model has a good accuracy in correlating the partitioning coefficients of biomolecules in aqueous two-phase systems.