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Coordination environment of Si in calcium silicate hydrates, silicate minerals, and blast furnace slags: A Xanes database

Li, Jiaqi [Hrsg.]; Zhang, Wenxin; Garbev, Krassimir; Monteiro, Paulo J. M.

Abstract (englisch):
Understanding the silicate polymerization of calcium silicate hydrate (C-S-H) gel and its crystalline polymorphs is important in cement science. NMR can determine Si environments, but the measurement can be timeconsuming and provides no spatial information. X-ray absorption near-edge structure (XANES) spectroscopy is a fast tool for probing Si coordination, possibly with spatial information. However, there lacks an understanding of Si K-edge XANES spectra of cement-related silicate phases. Here, a Si K-edge XANES spectral database of nanocrystalline C-S-H, C-S-H minerals, blast-furnace slags, and metakaolin is provided. Si K-edge of C-S-H minerals shifts to higher energies with higher polymerized Si and lower Ca–Si connectivity in the Si second nearest neighbor shell. Si K-edge energy shows weak correlations with Ca/Si ratio, average Si–O bond length, and SiO4 distortion due to the structural complexity of silicates. The substitution of Al for Si shifts the Si K-edge of tobermorite and slags to higher energies.



Zugehörige Institution(en) am KIT Institut für Technische Chemie (ITC)
Publikationstyp Zeitschriftenaufsatz
Publikationsdatum 02.02.2021
Sprache Englisch
Identifikator ISSN: 0008-8846, 1873-3948
KITopen-ID: 1000129525
HGF-Programm 38.05.02 (POF IV, LK 01) Metals and Minerals Cycle
Erschienen in Cement and concrete research
Verlag Elsevier
Heft 143
Schlagwörter XANES, X-ray absorption spectra, C-S-H, Tobermorite, Silicate polymerization
Nachgewiesen in Dimensions
Scopus
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