Cosolutes effects on aqueous two-phase systems equilibrium formation studied by physical approaches.
The effect of urea and sodium salts of monovalent halides on the aqueous polyethyleneglycol solution and binodal diagrams of polyethyleneglycol-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 affected 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.
Bertoluzzo
M Guadalupe
MG
Physical-Chemistry Department, Faculty of Biochemical and Pharmaceutical Sciences, National University of Rosario, FonCyT, CIUNR and CONICET, Suipacha 570, S2002RLK Rosario, Argentina.
Rigatuso
Rubén
R
Farruggia
Beatriz
B
Nerli
Bibiana
B
Picó
Guillermo
G
D003102:Colloids; D008970:Molecular Weight; D010710:Phosphates / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry*; D017680:Potassium Compounds / Q000737:chemistry; D012492:Salts / Q000737:chemistry; D012996:Solutions; D013816:Thermodynamics; D014508:Urea / Q000737:chemistry; D014867:Water / Q000737:chemistry*
D003102:Colloids; D010710:Phosphates; D017680:Potassium Compounds; D012492:Salts; D012996:Solutions; D014867:Water; D011092:Polyethylene Glycols; D014508:Urea; C013216:potassium phosphate