Interpretation of Hydrated States of Sodium Silicate Glasses by Infrared and Raman Analysis

Abstract

Infrared spectra of thin films (a few micrometers) of hydrated sodium silicate glasses after heating at temperatures from 100° to 400°C were measured in the spectral region from 400 to 4300 cm −1 . Also, Raman spectra of hydrated glasses were measured in the region from 100 to 1400 cm −1 . Water molecules in hydrated glasses were classified into three types by the bonding configuration: water molecules interacting with Si–OH groups, nonbridging oxygens, and bridging oxygens. On the basis of the fundamental bands observed here, we calculated the wave numbers of the combination‐overtone bands of water molecules and SiOH groups in hydrated glasses. The calculated wave numbers satisfactorily agreed with observed wave numbers in the nearinfrared region.