Anisotropic polyamide-polyether block copolymers doped with several cesium
salts were studied with Cs-133 NMR. These materials;are highly hydrophilic.
In the first set of experiments the evolution of the spectra was measured
as a function of the swelling ratio in H2O/D2O mixtures. The evolution of t
he spectral parameters (Cs-133 chemical shifts and the quadrupolar splittin
gs of Cs-133 and H-2) indicates that strong interactions exist between the
Csf ions and the polymeric chains. At high swelling ratios the cations free
ly probe the anisotropic property of the polyether chains. In a second set
of experiments dried materials were studied as a function of the sample tem
perature. Surprisingly, a significant increase in the anisotropic character
of the Csf reorientation was measured when the temperature was raised. The
increase of the electric field gradient could be considered as a measureme
nt of some "apparent ionic order", which would be related to the modificati
on of the averaged cation complexation site and to the dynamics of these io
ns. These measurements may serve as a new approach to the investigation of
the nature of ion-polymer interactions.