Details
| Original language | English |
|---|---|
| Pages (from-to) | 121-128 |
| Number of pages | 8 |
| Journal | Solid State Nuclear Magnetic Resonance |
| Volume | 9 |
| Issue number | 2-4 |
| Publication status | Published - Dec 1997 |
Abstract
The hydrothermal transformation of kaolinite to basic sodalite Na8[AlSiO4]6 (OH · H2O)2 and hydroxoborate sodalite Na8[AlSiO4]6 [B(OH)4]2 has been investigated at different temperatures (353 and 473 K). In the early stage of the reactions, the crystallization kinetics was studied by X-ray powder diffraction, thermogravimetry, IR spectroscopy and 29Si MAS NMR spectroscopy. Besides the crystallization of the sodalites, no further intermediate phases were formed. MAS NMR of the 29Si nucleus has been found to be a versatile tool to follow the progress of reactions from the signal ratio of the initial material and the crystallization product because the differences in chemical shifts result in well-separated signals. From these measurements, the growth rates of the sodalites could be determined quantitatively even for the very early stages of crystallization. It was found that sodium carbonate impurities in the NaOH solution used for the synthesis has an important influence on the reaction kinetics.
Keywords
- Si MAS NMR, Crystallization kinetics, Sodalite
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Radiation
- Chemistry(all)
- Physics and Astronomy(all)
- Nuclear and High Energy Physics
- Physics and Astronomy(all)
- Instrumentation
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In: Solid State Nuclear Magnetic Resonance, Vol. 9, No. 2-4, 12.1997, p. 121-128.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - The crystallization kinetics of sodalites grown by the hydrothermal transformation of kaolinite studied by 29Si MAS NMR
AU - Buhl, J. Chr
AU - Hoffmann, W.
AU - Buckermann, W. A.
AU - Müller-Warmuth, W.
PY - 1997/12
Y1 - 1997/12
N2 - The hydrothermal transformation of kaolinite to basic sodalite Na8[AlSiO4]6 (OH · H2O)2 and hydroxoborate sodalite Na8[AlSiO4]6 [B(OH)4]2 has been investigated at different temperatures (353 and 473 K). In the early stage of the reactions, the crystallization kinetics was studied by X-ray powder diffraction, thermogravimetry, IR spectroscopy and 29Si MAS NMR spectroscopy. Besides the crystallization of the sodalites, no further intermediate phases were formed. MAS NMR of the 29Si nucleus has been found to be a versatile tool to follow the progress of reactions from the signal ratio of the initial material and the crystallization product because the differences in chemical shifts result in well-separated signals. From these measurements, the growth rates of the sodalites could be determined quantitatively even for the very early stages of crystallization. It was found that sodium carbonate impurities in the NaOH solution used for the synthesis has an important influence on the reaction kinetics.
AB - The hydrothermal transformation of kaolinite to basic sodalite Na8[AlSiO4]6 (OH · H2O)2 and hydroxoborate sodalite Na8[AlSiO4]6 [B(OH)4]2 has been investigated at different temperatures (353 and 473 K). In the early stage of the reactions, the crystallization kinetics was studied by X-ray powder diffraction, thermogravimetry, IR spectroscopy and 29Si MAS NMR spectroscopy. Besides the crystallization of the sodalites, no further intermediate phases were formed. MAS NMR of the 29Si nucleus has been found to be a versatile tool to follow the progress of reactions from the signal ratio of the initial material and the crystallization product because the differences in chemical shifts result in well-separated signals. From these measurements, the growth rates of the sodalites could be determined quantitatively even for the very early stages of crystallization. It was found that sodium carbonate impurities in the NaOH solution used for the synthesis has an important influence on the reaction kinetics.
KW - Si MAS NMR
KW - Crystallization kinetics
KW - Sodalite
UR - http://www.scopus.com/inward/record.url?scp=0031283388&partnerID=8YFLogxK
U2 - 10.1016/S0926-2040(97)00052-0
DO - 10.1016/S0926-2040(97)00052-0
M3 - Article
C2 - 9477443
AN - SCOPUS:0031283388
VL - 9
SP - 121
EP - 128
JO - Solid State Nuclear Magnetic Resonance
JF - Solid State Nuclear Magnetic Resonance
SN - 0926-2040
IS - 2-4
ER -