IR-study of the phase composition of sodium silicate synthesized in aqueous medium

The distribution of components, phase composition, and structural features of sodium silicate synthesized in an aqueous medium were studied by IR spectroscopy. Long-term storage in air resulted in partial cracking of the substance and a change in its phase composition. The main phases were sodium silicates of different stoichiometry, free silica in the form of cristobalite, and sodium carbonate. When exposed to ambient conditions, the concentration gradients of sodium carbonate and water in the silicate material increased from the center to the edges. An explanation is given of the processes of initiation and development of cracks that violated the continuity of the synthesized substance. It is noted that water, which is sorbed from the air, is more dangerous for the degradation of the structure than structurally bound water from the initial solution. Tab. 1, ill. 3, bibliography: 11 titles.