Details
| Original language | English |
|---|---|
| Pages (from-to) | 13-20 |
| Number of pages | 8 |
| Journal | Microporous and Mesoporous Materials |
| Volume | 236 |
| Early online date | 24 Aug 2016 |
| Publication status | Published - 1 Dec 2016 |
Abstract
A new crystallization pathway composed of a combination of gel synthesis and crystallization in a melt flow is demonstrated using the sodalite system as a case study. The specific characteristics of this enhanced method of crystallization persists in a controlled heating of a pressed pellet of a mixture of selected solids, containing a “water donator” as well as a “fluxing agent”. The reaction of zeolite 13 X (“water donator and Si[sbnd]Al-source”) NaOH granulate (“fluxing agent”) and a template salt like NaCl (or others) is shown to yield suitable products already after a few hours of heating the mix-pellet under open conditions. In a first synthesis series experiments were performed to investigate the details of the reaction mechanism. Beside a study of the role of the hydrate water, the NaOH granulate and certain template salts, even the total decomposition of the zeolite 13 X framework structure could be demonstrated under the conditions of the crossover from gel to flux growth. According to the results it could be claryfied that the mechanism consists of alkaline aluminosilicate gel formation and crystallization in the early period but shifts into crystal growth in NaOH melt at elevated temperature. In a second series examples of tailored sodalites and the characterization of these products will show the effectiveness of the new method. From SEM invertigations could be further derived that the crystal size and morphology depends on Tmax. the holding period at Tmax. and nano- or micro-crystalline sodalites can be obseved.
Keywords
- Crystallization, Flux synthesis, Hydrothermal synthesis, Tailor-made sodalites
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
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Microporous and Mesoporous Materials, Vol. 236, 01.12.2016, p. 13-20.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Enhanced methods of crystallization
T2 - The crossover synthesis from gel to melt flow - A case study on sodalites
AU - Buhl, J. Ch
PY - 2016/12/1
Y1 - 2016/12/1
N2 - A new crystallization pathway composed of a combination of gel synthesis and crystallization in a melt flow is demonstrated using the sodalite system as a case study. The specific characteristics of this enhanced method of crystallization persists in a controlled heating of a pressed pellet of a mixture of selected solids, containing a “water donator” as well as a “fluxing agent”. The reaction of zeolite 13 X (“water donator and Si[sbnd]Al-source”) NaOH granulate (“fluxing agent”) and a template salt like NaCl (or others) is shown to yield suitable products already after a few hours of heating the mix-pellet under open conditions. In a first synthesis series experiments were performed to investigate the details of the reaction mechanism. Beside a study of the role of the hydrate water, the NaOH granulate and certain template salts, even the total decomposition of the zeolite 13 X framework structure could be demonstrated under the conditions of the crossover from gel to flux growth. According to the results it could be claryfied that the mechanism consists of alkaline aluminosilicate gel formation and crystallization in the early period but shifts into crystal growth in NaOH melt at elevated temperature. In a second series examples of tailored sodalites and the characterization of these products will show the effectiveness of the new method. From SEM invertigations could be further derived that the crystal size and morphology depends on Tmax. the holding period at Tmax. and nano- or micro-crystalline sodalites can be obseved.
AB - A new crystallization pathway composed of a combination of gel synthesis and crystallization in a melt flow is demonstrated using the sodalite system as a case study. The specific characteristics of this enhanced method of crystallization persists in a controlled heating of a pressed pellet of a mixture of selected solids, containing a “water donator” as well as a “fluxing agent”. The reaction of zeolite 13 X (“water donator and Si[sbnd]Al-source”) NaOH granulate (“fluxing agent”) and a template salt like NaCl (or others) is shown to yield suitable products already after a few hours of heating the mix-pellet under open conditions. In a first synthesis series experiments were performed to investigate the details of the reaction mechanism. Beside a study of the role of the hydrate water, the NaOH granulate and certain template salts, even the total decomposition of the zeolite 13 X framework structure could be demonstrated under the conditions of the crossover from gel to flux growth. According to the results it could be claryfied that the mechanism consists of alkaline aluminosilicate gel formation and crystallization in the early period but shifts into crystal growth in NaOH melt at elevated temperature. In a second series examples of tailored sodalites and the characterization of these products will show the effectiveness of the new method. From SEM invertigations could be further derived that the crystal size and morphology depends on Tmax. the holding period at Tmax. and nano- or micro-crystalline sodalites can be obseved.
KW - Crystallization
KW - Flux synthesis
KW - Hydrothermal synthesis
KW - Tailor-made sodalites
UR - http://www.scopus.com/inward/record.url?scp=84984655333&partnerID=8YFLogxK
U2 - 10.1016/j.micromeso.2016.08.021
DO - 10.1016/j.micromeso.2016.08.021
M3 - Article
AN - SCOPUS:84984655333
VL - 236
SP - 13
EP - 20
JO - Microporous and Mesoporous Materials
JF - Microporous and Mesoporous Materials
SN - 1387-1811
ER -