Physicochemical characterization of the PEG8000-Na2SO4 aqueous two-phase system

• Autor(es): Rodríguez, Oscar ; Silvério, Sara C. ; Madeira, Pedro ; Teixeira, J. A. ; Macedo, Eugénia
• Data: 2007
• Identificador Persistente: http://hdl.handle.net/1822/7348
• Origem: RepositóriUM - Universidade do Minho
• Tipo de Documento: Artigo
• Idioma: Inglês

Descrição

The polyethylene glycol-sodium sulfate aqueous two-phase system has been characterized at 23 °C. Tielines for the phase diagram were obtained experimentally. Phases in equilibrium were characterized by means of the solvatochromic parameters π*, α, and β, which provide a measurement of the polarity/polarizability and the H-bond donor and acceptor abilities, respectively. The ability of the phases to participate in hydrophobic interactions was characterized by means of the free energy of transfer of a methylene group between the conjugated phases, using the partition of a homologous series of dinitrophenylated amino acids. The results show the effect of the presence of polymer and salt in the aqueous phase, and a comparison of both phases with pure water is made.