Résumé:
Because water molecules have a relatively large permanent electric dipole moment, their whole molecular motions are clearly detectable using extremely high frequency dielectric spectrum measurements.  Moreover, free and hydrated water molecules in aqueous solutions are easily distinguished from dielectric spectra.  By use of the extremely high frequency dielectric techniques, one can precisely determine hydration numbers of some polymeric materials, e.g., poly(ethylene glycol) and poly(vinyl alcohol)) as functions of temperature. Simultaneously, information on segment motions for the polymers in aqueous solution is also detectable.  Hydration behavior and dynamics of such the polymeric materials in aqueous solution will be shown.