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A thermosyphon‐driven hydrothermal flow‐through cell for in situ and time‐resolved neutron diffraction studies
Author(s) -
Xia Fang,
O'Neill Brian,
Ngothai Yung,
Peak Jason,
Tenailleau Christophe,
Etschmann Barbara,
Qian Gujie,
Brugger Joël,
Studer Andrew,
Olsen Scott,
Pring Allan
Publication year - 2010
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889810006990
Subject(s) - neutron diffraction , hydrothermal circulation , materials science , diffractometer , crystallization , analcime , phase (matter) , powder diffraction , crystallography , acicular , chemical engineering , chemistry , scanning electron microscope , thermodynamics , metallurgy , composite material , physics , crystal structure , zeolite , biochemistry , organic chemistry , engineering , catalysis , microstructure
A flow‐through cell for hydrothermal phase transformation studies by in situ and time‐resolved neutron diffraction has been designed and constructed. The cell has a large internal volume of 320 ml and can operate at temperatures up to 573 K under autogenous vapor pressures ( ca 8.5 × 10 6 Pa). The fluid flow is driven by a thermosyphon, which is achieved by the proper design of temperature difference around the closed loop. The main body of the cell is made of stainless steel (316 type), but the sample compartment is constructed from non‐scattering Ti–Zr alloy. The cell has been successfully commissioned on Australia's new high‐intensity powder diffractometer WOMBAT at the Australian Nuclear Science and Technology Organization, using two simple phase transformation reactions from KAlSi 2 O 6 (leucite) to NaAlSi 2 O 6 ·H 2 O (analcime) and then back from NaAlSi 2 O 6 ·H 2 O to KAlSi 2 O 6 as examples. The demonstration proved that the cell is an excellent tool for probing hydrothermal crystallization. By collecting diffraction data every 5 min, it was clearly seen that KAlSi 2 O 6 was progressively transformed to NaAlSi 2 O 6 ·H 2 O in a sodium chloride solution, and the produced NaAlSi 2 O 6 ·H 2 O was progressively transformed back to KAlSi 2 O 6 in a potassium carbonate solution.