The influence of sucrose on the crystallization behaviour in the system CaO-SiO{sub 2}-C{sub 12}H{sub 22}O{sub 11}-H{sub 2}O under hydrothermal conditions

Journal Article · Thu Apr 15 00:00:00 EDT 2010 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2009.12.033· OSTI ID:22202569

Buhl, J. -Ch. ^[1]

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1. Institut fuer Mineralogie, Leibniz Universitaet Hannover, D-30167 Hannover (Germany)

Hydrothermal synthesis in the presence of sucrose has been carried out at 200 {sup o}C and autogeneous pressure in the system CaO-SiO{sub 2}-C{sub 12}H{sub 22}O{sub 11}-H{sub 2}O to investigate the influence of C{sub 12}H{sub 22}O{sub 11} on phase formation and the crystal habit of calcium silicate hydrates (CSH-phases). A sucrose/lime ratio of 0.5 was utilized in all experiments and the reactivity of the SiO{sub 2} source was varied using educts of different grain size of {approx}40 mesh and >230 mesh. CaO/SiO{sub 2} concentration ratios of 0.5 and 0.8 have been selected, the latter with respect to the composition of the important CSH-phase 11 A tobermorite. The results were compared with experiments under similar but sucrose-free conditions. X-ray powder diffraction (XRD), scanning electron microscopy (SEM) combined with energy dispersive X-ray analysis (EDX-analysis) as well as Fourier transform infrared spectroscopy (FTIR-spectroscopy) have been applied for analyses. A retarding effect of sucrose on CSH-phase formation has been observed. Only minor amount of CSH without regular morphology was observed instead of typically fibrous 11 A tobermorite formed in the sucrose-free system. Sucrose altered the reaction mechanism in the CSH-system and hydrothermal process started with rapid reaction of sucrose and lime. The further course of crystallization was dominated by an extended precipitation of calcium carbonate and small amounts of calcium oxalate hydrate. Formation of these stable hydrothermal decomposition products of saccharated lime is strongly suppressing the CSH-crystallization.

• OSTI ID: 22202569
• Journal Information: Materials Research Bulletin, Vol. 45, Issue 4; Other Information: Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTROSCOPY
CALCIUM
CALCIUM CARBONATES
CALCIUM OXIDES
CALCIUM SILICATES
CRYSTAL STRUCTURE
CRYSTALLIZATION
CRYSTALS
FOURIER TRANSFORM SPECTROMETERS
FOURIER TRANSFORMATION
GRAIN SIZE
HYDROTHERMAL SYNTHESIS
INFRARED SPECTRA
REACTION KINETICS
SACCHAROSE
SCANNING ELECTRON MICROSCOPY
SILICA
SILICON OXIDES
X RADIATION
X-RAY DIFFRACTION