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

Abstract

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 d_P-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.