RAMAN SPECTRAL STUDIES OF SIO2-NAOH-H2O SYSTEM SOLUTION UNDER HYDROTHERMAL CONDITIONS

Raman spectra of the SiO2-NaOH-H2O system solution that was prepared by a reaction of 1 NaOH solution with SiO2 under the conditions of hydrothermal growth of Δ-quartz were measured in the range of room temperature to 320°C for the spectral region of about 50-4000 cm-1 by use of an autoclave (V=0.50 cm3) with sapphire windows. The solution, with a mole ratio of Na2O to SiO2 of 0.56, contains monomers, dimers, trimers and polysilicic ions, etc., and has at Raman spectrum peaks at 175, 430b, 600b, 780, 1035, 1645, 3200 and 3400 cm-1 at room temperature. The Raman spectrum peaks 780 and 1035 cm-1 were observed at 300°C. © 1990.