Effect of sodium chloride on gelatinization of silicic acid and the formation of novel polysilicic acid crystals

Silicic acid high purity was produced by passing sodium silicate solution under pressure through a column packed with ion exchange resin. The effect of sodium chloride concentration on the gel formation process was studied. We proposed that, besides amorphous sol, chain-like compounds were also formed in the silicic acid gelatinization process. Polysilicic acid solution was obtained by slow polymerization of the silicic acid at lower temperature. Some organic solvents were added to this solution at room temperature, resulting in a novel material species – partial crystallized polysilicic acid powder. Characterization techniques such as XRD, IR, TEM, TGA and DTA were used to investigate the materials. The new findings in the present study supported the previously proposed mechanism for silicic acid chain polymerization.