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Formation Processes of β‐C 2 S by the Decomposition of Hydrothermally Prepared C‐S‐H with Ca(OH) 2
Author(s) -
Okada Yoshihiko,
Sasaki Kaori,
Zhong Baiqian,
Ishida Hideki,
Mitsuda Takeshi
Publication year - 1994
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1994.tb05409.x
Subject(s) - thermal decomposition , decomposition , dimer , silicic acid , polymerization , monomer , chemistry , hydrothermal circulation , silicate , hydrothermal synthesis , polymer , silicic , nuclear chemistry , polymer chemistry , inorganic chemistry , chemical engineering , organic chemistry , engineering , volcano , seismology , geology
A mixture of CaO and silicic acid prepared with a Ca/Si ratio of 2.0 was hydrothermally synthesized at 80° to 200°C, and the thermal decomposition behavior of the products (C‐S‐H with Ca(OH) 2 ) was analyzed using XRD, 29 Si MAS NMR, and the trimethylsililation method (TMS). It was found that the main silicate anion structure of C‐S‐H was a mixture of a dimer and a single‐chain polymer (larger than Si 5 O 16 ) and that polymerization advanced with an increase of the synthesizing temperature. On heating, the products decomposed to form β‐C 2 S. It was found that the decomposition was gradual and that the‐higher the temperature of hydrothermal synthesis, the lower was the temperature of the decomposition into β‐C 2 S. Although the decomposition proceeded to form a monomer (β‐C 2 S) from the polymer and dimer, this dimer was resistant to heat and did not decompose unless heated to above 400°C.