Structural investigation of hydrous sodium borosilicate glasses

The increase of band components in the Raman spectra near 900 cm− 1 relative to the region > 1050 cm− 1 gives evidence for depolymerization of the network upon hydration. Fitting of the spectra with Gaussians implies that silica tetrahedra with two non-bridging oxygen (Q2) are preferentially formed by reaction with water on expense of tetrahedra linked to four tetrahedra (Q4).