Dissociation, molweight, and vibrational spectra of aqueous sodium silicate solutions

摘要

Particles in 3 to 0.2 mole SiO2/L aqueous Na-silicate solutions are only partially dissociated. Their average molweight (AMW) varies with their Na/Si ratio and concentration. Combined molecular spectroscopic and AMW measurements suggest that only some of the most diluted solutions contain overwhelmingly monomer silicate anions and the average silicate particles contain more than 10 [SiO4] tetrahedral units in some of the more concentrated solutions. Both the dissociation and the hydrolysis affect the FTIR and Raman spectra of dissolved silicates making the revision of some earlier band assignments necessary.