Solvent dynamics in aqueous PEO–salt solutions studied by nuclear magnetic relaxation

The dynamical behaviour of water in aqueous PEO solutions has been studied by 2H and 17O nuclear magnetic relaxation measurements. A two-phase model is introduced to analyse the water mobility in the PEO hydration phase. The water mobility in the hydrated phase is retarded by a factor of 2 to 5. The anisotropic reorientation of water molecules in the proximity of PEO and the dP-dependence on the 2H and 17O relaxation rates are interpreted qualitatively by local PEO dynamics, preferential orientations of water molecules and deuteron exchange among water molecules and hydroxy end-groups.