STUDY OF THE POLYMERIZATION OF SILICIC ACID ADSORBED ON IRON(III) HYDROXIDE BY TRIMETHYLSILYLATION-GAS CHROMATOGRAPHY.

Polymerization of silicic acid adsorbed on iron (III) hydroxide from dilute monosilicic acid solutions in the concentration range 5-40 ppm (SiO//2) was studied over the pH range 6-12. Silicic acid species formed on the hydroxide were trimethylsilylated and trimethylsilyl derivatives were detected by gas chromatography. Monosilicic acid adsorbed polymerized, and dimer (Si//2O//7**6** minus ), linear trimer (Si//3O//1//0**8** minus ) and tetramer (Si//4O//1//3**1**0** minus ), and cyclic tetramer (Si//4O//1//2**8** minus ) were found as polymeric species.