Details
| Original language | English |
|---|---|
| Pages (from-to) | 110-117 |
| Number of pages | 8 |
| Journal | Microporous and Mesoporous Materials |
| Volume | 171 |
| Early online date | 23 Dec 2012 |
| Publication status | Published - 1 May 2013 |
Abstract
Low temperature (333 K) crystallization of hyperalkaline carbonate containing aluminosilicate gels has been studied. Nanocrystalline carbonate enclathrated zeolite-type with intermediate structure between sodalite and cancrinite was observed already after 3 h. Its crystal size was found to be around 40 nm over synthesis periods from 3 h to 96 h. A further experimental series was performed under addition of triethanolamine to study its effect on crystallization kinetics, crystal size and morphology. Nucleation deceleration of aluminosilicates but recrystallization of large crystals of sodium carbonate could be revealed in the early stage of these reactions. As a result big elongated rectangular hollow plates of the intermediate phase composed of small spherical crystal aggregates consisting of numerous nanocrystallites were observed. Heterogeneous nucleation and growth of the intermediate phase on the surfaces of the previously formed big plate-like Na2CO3 crystals was responsible for this unusual particle aggregation. All products were characterized by X-ray powder diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and simultaneous thermal analysis. The intermediate phase were compared with microcrystalline carbonate-cancrinite and hydro-sodalite of common synthesis at 473 K. The thermal and hydrothermal behavior of the nanocrystalline intermediate phase was further characterized and discussed in terms of its specific structural features. Compared with microcrystalline cancrinite remarkable thermal stability could be stated. In contrast a much higher decomposition rate of the intermediate phase under hydrothermal stress was observed.
Keywords
- Hydrothermal behavior, Nanocrystalline solids, Stacking disorder, Thermal stability, Zeolites
ASJC Scopus subject areas
- Chemistry(all)
- General Chemistry
- Materials Science(all)
- General Materials Science
- Physics and Astronomy(all)
- Condensed Matter Physics
- Engineering(all)
- Mechanics of Materials
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In: Microporous and Mesoporous Materials, Vol. 171, 01.05.2013, p. 110-117.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - The intermediate phase between sodalite and cancrinite
T2 - Synthesis of nano-crystals in the presence of Na2CO3/TEA and its thermal- and hydrothermal stability
AU - Grader, Corinna
AU - Buhl, Josef Christian
PY - 2013/5/1
Y1 - 2013/5/1
N2 - Low temperature (333 K) crystallization of hyperalkaline carbonate containing aluminosilicate gels has been studied. Nanocrystalline carbonate enclathrated zeolite-type with intermediate structure between sodalite and cancrinite was observed already after 3 h. Its crystal size was found to be around 40 nm over synthesis periods from 3 h to 96 h. A further experimental series was performed under addition of triethanolamine to study its effect on crystallization kinetics, crystal size and morphology. Nucleation deceleration of aluminosilicates but recrystallization of large crystals of sodium carbonate could be revealed in the early stage of these reactions. As a result big elongated rectangular hollow plates of the intermediate phase composed of small spherical crystal aggregates consisting of numerous nanocrystallites were observed. Heterogeneous nucleation and growth of the intermediate phase on the surfaces of the previously formed big plate-like Na2CO3 crystals was responsible for this unusual particle aggregation. All products were characterized by X-ray powder diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and simultaneous thermal analysis. The intermediate phase were compared with microcrystalline carbonate-cancrinite and hydro-sodalite of common synthesis at 473 K. The thermal and hydrothermal behavior of the nanocrystalline intermediate phase was further characterized and discussed in terms of its specific structural features. Compared with microcrystalline cancrinite remarkable thermal stability could be stated. In contrast a much higher decomposition rate of the intermediate phase under hydrothermal stress was observed.
AB - Low temperature (333 K) crystallization of hyperalkaline carbonate containing aluminosilicate gels has been studied. Nanocrystalline carbonate enclathrated zeolite-type with intermediate structure between sodalite and cancrinite was observed already after 3 h. Its crystal size was found to be around 40 nm over synthesis periods from 3 h to 96 h. A further experimental series was performed under addition of triethanolamine to study its effect on crystallization kinetics, crystal size and morphology. Nucleation deceleration of aluminosilicates but recrystallization of large crystals of sodium carbonate could be revealed in the early stage of these reactions. As a result big elongated rectangular hollow plates of the intermediate phase composed of small spherical crystal aggregates consisting of numerous nanocrystallites were observed. Heterogeneous nucleation and growth of the intermediate phase on the surfaces of the previously formed big plate-like Na2CO3 crystals was responsible for this unusual particle aggregation. All products were characterized by X-ray powder diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and simultaneous thermal analysis. The intermediate phase were compared with microcrystalline carbonate-cancrinite and hydro-sodalite of common synthesis at 473 K. The thermal and hydrothermal behavior of the nanocrystalline intermediate phase was further characterized and discussed in terms of its specific structural features. Compared with microcrystalline cancrinite remarkable thermal stability could be stated. In contrast a much higher decomposition rate of the intermediate phase under hydrothermal stress was observed.
KW - Hydrothermal behavior
KW - Nanocrystalline solids
KW - Stacking disorder
KW - Thermal stability
KW - Zeolites
UR - http://www.scopus.com/inward/record.url?scp=84873286209&partnerID=8YFLogxK
U2 - 10.1016/j.micromeso.2012.12.023
DO - 10.1016/j.micromeso.2012.12.023
M3 - Article
AN - SCOPUS:84873286209
VL - 171
SP - 110
EP - 117
JO - Microporous and Mesoporous Materials
JF - Microporous and Mesoporous Materials
SN - 1387-1811
ER -