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Experimental Study and Thermodynamic Modeling of Process Partitioning of Penicillin in Polymer-Salt Aqueous Two-Phase Systems

Pazuki, Gholamreza | 2009

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  1. Type of Document: Ph.D. Dissertation
  2. Language: Farsi
  3. Document No: 39780 (06)
  4. University: Sharif University of Technology
  5. Department: Chemical and Petroleum Engineering
  6. Advisor(s): Taghikhani, Vahid; Vossoughi, Manouchehr
  7. Abstract:
  8. In this research, the partitioning of Penicillin G-Acylase in aqueous two-phase systems (ATPS) containing poly ethylene glycol (PEG) 20000 or 35000 and potassium di-hydrogen phosphate (KH2PO4) or sodium citrate (C6H5Na3O7.5H2O) is measured at three temperature (301.2, 307.2 and 310.2) K. The effects of temperature, polymer molecular weight, polymer and salt concentrations on partitioning of Penicillin G in the aqueous two-phase systems are studied. The experimental data showed that composition of salt has a large effect on partitioning of Penicillin G in ATPS and temperature of system has small effect on the partitioning. The modified local composition model was used to obtain the activity coefficients of amino acids and simple peptides in non-electrolyte aqueous solutions. The proposed model is used to obtaining solubilities of amino acids in water. Also the modified model is coupled with the modified electrolyte model to correlate the mean ionic activity coefficients of electrolytes in aqueous amino acid solutions.
    Also, the proposed model is investigated in obtaining thermophysical properties of polymer solutions such activity of solvent, density, viscosity and excess enthalpy. The proposed model is developed for electrolyte solutions. The results of the model are compared with those obtained from the NRTL, Wilson, UNIQUAC and Pitzer models. The developed model is also applies in correlating phase behavior of polymer-polymer and polymer-salt aqueous two-phase systems as well as process partitioning of biomolcules in aqueous two-phase systems. An expression for the free volume Gibbs energy model based on the local composition concept (LCC) is proposed in correlating the solubility, the partitioning and the surface tension of -lactam, tetracycline, fluoroquinolone and chloramphenicol antibiotic groups in water, alcohol, ketone, trihalomethane, ether and ester solvent groups. A new group contribution model is suggested for obtaining the thermodynamic properties of biomolecules in aqueous solutions. Accordingly, a Freed-FV model is applied for the combinatorial term “free-volume”. Activity coefficient, solubility, density, vapor pressure, osmotic pressure and partitioning of biomolecules in aqueous solutions are correlated using the proposed group contribution model. Group interaction parameters of the proposed model are obtained by use of experimental data from biomolecules available in the literature. In continue, the artificial neural network model is used to model the partition coefficients of biomolecules in polymer-polymer aqueous two-phase systems. Finally, protein partitioning in polymer-salt aqueous two-phase systems is studied by the SAFT equation of state (EOS). The results show that the local composition based models and the SAFT equation of state can accurate correlate and predict phase behavior of biomolecule solution.
  9. Keywords:
  10. Aqueous Two-Phase System ; Modeling ; Penicillin G Acylase Enzyme ; Partitioning ; Local Composition ; Statistical Assosiating Fluids Theory (SAFT)

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