Phase Diagrams of the Aqueous Two-Phase Systems of Poly(ethylene glycol)/Sodium Polyacrylate/Salts

Polymers

Hans-Olof Johansson²  Eloi Feitosa¹ 

[1] Department of Physics, IBILCE/UNESP, São Paulo State University, Rua Cristovão Colombo, 2265, SP, CEP 15054-000, São Jose do Rio Preto, Brazil; E-Mail:;Department of Biochemistry and Structural Biology, University of Lund, P.O. Box 124, SE-221 00 Lund, Sweden

关键词: poly(ethylene glycol);    sodium polyacrylate;    ATPS;    Flory-Huggins theory;    phase diagram;    hydrophobic ions;   

DOI  :  10.3390/polym3010587

来源: mdpi

【 摘 要 】

Aqueous two-phase systems consisting of polyethylene glycol (PEG), sodium polyacrylate (NaPAA), and a salt have been studied. The effects of the polymer size, salt type (NaCl, Na₂SO₄, sodium adipate and sodium azelate) and salt concentrations on the position of the binodal curve were investigated. The investigated PEG molecules had a molar mass of 2,000 to 8,000 g/mol, while that of NaPAA was 8,000 g/mol. Experimental phase diagrams, and tie lines and calculated phase diagrams, based on Flory-Huggins theory of polymer solutions are presented. Due to strong enthalpic and entropic balancing forces, the hydrophobicity of the added salt has a strong influence on the position of the binodal, which could be reproduced by model calculations.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.