THERMODYNAMIC STUDY OF POLYETHYLENE-GLYCOLS IN MICELLAR SOLUTIONS WATER PLUS SODIUM DODECYL-SULFATE

Interactions of a series of polyethyleneglycols (PEG) in aqueous micel lar solutions of sodium dodecylsulfate (SDS) were investigated through thermodynamic properties. Volumes, heat capacities and enthalpies of dilution were measured at 25-degrees-C. The resulting transfer propert ies of PEG are reflecting hydrophobic interactions which increase with the polymer length and the hydrophilic interactions occurring in the aqueous polar layer of the micelles. Typically heat capacities clearly evidence various structural changes taking place in the micellar solu tions.