Linear rheological properties of low molecular weight polyethylene glycol solutions.

This experimental study of the linear viscoelastic properties of PEG600 aqueous solutions at various concentrations and temperatures mainly aims at getting a better understanding, in concentrated regimes, of the role played on the structural and rheological properties by PEG assembly properties previously evidenced in the dilute regime. The results indicate a peculiar and unique viscoelastic behavior: the elastic modulus versus frequency curves are nearly the same for all concentrations and temperatures investigated. The key role played by hydrogen bonds in the rheological properties of PEG solutions is highlighted.

Polyethylene glycol aggregates in water formed through hydrophobic helical structures.

The present study was aimed at elucidating the mechanism of aggregation in water of hydroxyl-terminated polyethylene glycol (PEG) of low molecular weight (600 g/mol). The results from fluorescence spectroscopy at different temperatures were consistent with surface tension measurements, suggesting aggregate formation. Indeed, the process of aggregation is accompanied by an increase in the fluorescence emission of a hydrophobic probe.