Cosolutes effects on aqueous two-phase systems equilibrium

M. GUADALUPE BERTOLUZZO,; RUBEN RIGATUSO; BEATRIZ FARRUGGIA; BIBIANA NERLI; GUILLERMO PICÓ

Colloids and Surfaces B: Biointerfaces

elsevier

Lugar: Dublin; Año: 2007 vol. 59 p. 134 - 140

The effect of urea and sodium salts of monovalent halides on the aqueous polyethyleneglycol solution and binodal diagrams of olyethyleneglycol–potassium phosphate (polyethyleneglycol of molecular mass 1500, 4000, 6000 and 8000) were studied using different physical approaches. The effect of these solutes on the binodal diagram for polyethyleneglycol–potassium phosphate was also investigated. The cosolutes ffected in a significant manner the water structured around the ethylene chain of polyethyleneglycol inducing a lost of this. The equilibrium curves  for the aqueous two-phase systems were fitting very well by a sigmoidal function with two parameters, which are closely related with the cosolute structure making or breaking capacity on the water ordered.