Study of the polymerization of silicic acid in aqueous solution by trimethylsilylation—gas chromatography

✍ Scribed by Tsugio Shimono; Toshiyuki Isobe; Toshikazu Tarutani

• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 404 KB
• Volume: 258
• Category: Article
• ISSN: 1873-3778
• DOI: 10.1016/s0021-9673(00)96399-4

✦ Synopsis

The effects of pH, concentration of monosilicic acid and temperature on the formation of low-molecular-weight silicic acid species in the early stages of polymerization were studied by trimethylsilylation-gas chromatography (TM%GC). The change with time in the distribution of silicic acid species up to the hexamer was measured. The results obtained by TMS-GC are compared with those obtained by calorimetry. In solutions of initial monosilicic acid concentration of 600 ppm SiO, at pH 18,2O"C and at pH 8.5,90%, it was found that a temporary equilibrium is set up among SiOi-, S&O?-and Si,Oy, during the induction period. On the other hand, for 2500 and 5000 ppm SiO, solutions at pH 1.8, 2O"C, higher-molecular-weight silicic acid species than Si,Of; were formed during the induction period, and the distribution of these species changed with time. All of the silicic acid species formed during the induction period, and the distribution of these species changed with time. All of the silicic acid species formed during the induction period were determined by calorimetry.