Stable solutions of orthosilicic acid

Abstract

Soluble silicon plays a significant role in living organisms. Orthosilicic acid is the only bioavailable form of silicon. Sodium silicate solutions with various silicate moduli and different types of acids were used in our work to investigate the effect of silicate modulus and types of acids on the stability of the solutions of orthosilicic acid. It was determined that both the silicate modulus and the type of acid have a certain impact on the stability of orthosilicic acid solution. The effect of sulfuric, hydrochloric, orthophosphoric and methanesulfonic acid on the stability of orthosilicic acid solutions was studied depending on the silicate modulus of sodium silicate. It was shown that in the following series of anions SO42–, Cl–, CH3SO3–, PO43–, the stability of orthosilicic acid solutions increases. In the following series of alkaline modulus 3.02, 2.72, 2.06, 1.96, the stability increases too. The use of orthophosphoric acid and liquid glass with a silicate modulus of 1.96 allowed obtaining a solution, which is stable for at least 40 days.