STRUCTURE OF HYDRATED LAYERS ON SILICATE ELECTRODE GLASSES

The structural changes of the silicate framework in hydrated layers of silicate electrode glasses compared with untreated glasses as well as the quality and quantity of water and its ionic species stored in the layer have been investigated by high-resolution solid-state nuclear m agnetic resonance (NMR) techniques [Si-29 magic-angle spinning (MAS), Si-29 cross-polarization (CP) MAS, H-1 high-speed MAS, H-1 CRAMPS and H-1 Echo NMR]. To support the results, infrared (IR) spectroscopy, the rmal analysis and sodium ion concentration analyses were used. It was found that at least two different water species exist in the hydrated layer: SiOH groups and not very mobile hydrogen-bonded molecular water . Concerning the framework modified, Q3 groups [(SiO)3SiOH] were forme d in the hydrated glass. During the swelling process a condensation of silanol groups formed took place to a great extent.