Mechanisms of Incipient Chemical Reaction between Ca(OH)2and SiO2under Moderate Mechanical Stressing

✍ Scribed by Tomoyuki Watanabe; Tetsuhiko Isobe; Mamoru Senna

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 259 KB
• Volume: 130
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1997.7338

✦ Synopsis

The structure of mechanically induced precursor in an amorphous state between Ca(OH) 2 and SiO 2 was determined by solid state MAS and CP/MAS 29 Si NMR spectroscopies, and the changes in the behavior of crystallization by linear heating were studied by X-ray diffractometry. A large broad Q 0 peak due to the short-range order of hydrated calcium silicates appeared in the 29 Si NMR spectra of mechanically induced precursors. The formation of the new ordering is confined in the near-surface region of SiO 2 particles, as confirmed by comparing MAS and CP/MAS NMR spectra. When the amorphous precursor obtained above was subsequently heated, a rapid solid state reaction led to single phased -CaSiO 3 as the final product.