Investigating water vapour sorption kinetics of aluminium MOFs by powder X-ray diffraction

CrystEngComm ◽  
2019 ◽  
Vol 21 (15) ◽  
pp. 2551-2558 ◽  
Author(s):  
Dominik Fröhlich ◽  
Philipp Hügenell ◽  
Helge Reinsch
Keyword(s):  
Water Vapour ◽  
Water Sorption ◽  
Sorption Kinetics ◽  
X Ray Diffraction ◽  
Sorption Behaviour ◽  
Water Vapour Sorption ◽  
X Ray ◽  
Vapour Sorption ◽  
Kinetics Of

The water sorption behaviour of aluminium MOF CAU-10 and CAU-15-Cit was followed by in situ powder X-ray diffraction.

Analysis of the water vapour sorption behaviour of Sitka spruce [Picea sitchensis (Bongard) Carr.] based on the parallel exponential kinetics model

Holzforschung ◽  
2010 ◽  
Vol 64 (4) ◽  
Author(s):  
Callum A.S. Hill ◽  
Andrew Norton ◽  
Gary Newman
Keyword(s):  
Water Vapour ◽  
Sitka Spruce ◽  
Sorption Kinetics ◽  
Picea Sitchensis ◽  
Sorption Kinetic ◽  
Sorption Behaviour ◽  
Water Vapour Sorption ◽  
Vapour Sorption ◽  
Different Temperatures

Abstract The water vapour sorption behaviour of Sitka spruce was analysed based on the parallel exponential kinetics (PEK) model. The PEK model deconvolutes the sorption kinetics curve into two exponential kinetics processes (fast and slow) which have characteristic times and moisture contents associated with them. The sorption kinetics was examined at different temperatures enabling the determination of activation energies for the sorption kinetic processes throughout the hygroscopic range (from 5% to 95% relative humidities). The physical interpretation of the PEK model is also discussed.

Water vapour sorption of wood modified by acetylation and formalisation – analysed by a sorption kinetics model and thermodynamic considerations

Holzforschung ◽  
2016 ◽  
Vol 70 (3) ◽  
pp. 203-213 ◽  
Author(s):  
Sarah Himmel ◽  
Carsten Mai
Keyword(s):  
Cell Wall ◽  
Water Vapour ◽  
Sorption Process ◽  
Sorption Kinetics ◽  
Constant Factor ◽  
Sorption Data ◽  
Sorption Behaviour ◽  
Water Vapour Sorption ◽  
Vapour Sorption ◽  
Surface Work

Abstract The water vapour sorption data of untreated (Wuntr), acetylated (Wac) and formaldehyde-treated (WFA) Scots pine (Pinus sylvestris L.) sapwood were analysed in terms of their sorption kinetics and were transformed into excess surface work (ESW) isotherms. The sorption kinetics were studied by fitting the non-linear parallel exponential kinetics (PEK) model to the experimental data in which the sorption kinetics curve is composed of two processes (fast and slow components). Wac and WFA showed evident differences in their sorption kinetics and their thermodynamic sorption behaviour. In contrast to acetylation, formalisation influenced both the extent of the slow sorption process and the shape of its pseudoisotherm. For Wuntr and Wac, it appears that some water associated with the slow process is adsorbed at sites for fast sorption newly generated upon swelling (previously postulated as extra water) and subsequently desorbed by the fast process. For WFA, the formation of extra water hardly occurs. ESW was reduced through acetylation with a constant factor over the whole hydroscopic range, whereas the ESW of WFA was reduced only after reaching the monolayer capacity compared to its control. The sorption behaviour of Wac was solely determined by cell wall bulking, whereas that of WFA was governed by the increased matrix stiffness due to cross-linking of the cell wall polymers.

scholarly journals In situ monitoring of hydrothermal reactions by X-ray diffraction with Bragg–Brentano geometry

2020 ◽  
Vol 53 (4) ◽  
pp. 1163-1166
Author(s):  
Karsten Mesecke ◽  
Winfried Malorny ◽  
Laurence N. Warr
Keyword(s):  
Quantitative Information ◽  
In Situ Monitoring ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Saturated Vapour Pressure ◽  
Concrete Production ◽  
Aerated Concrete ◽  
Kinetics Of

This note describes an autoclave chamber developed and constructed by Anton Paar and its application for in situ experiments under hydrothermal conditions. Reactions of crystalline phases can be studied by successive in situ measurements on a conventional laboratory X-ray diffractometer with Bragg–Brentano geometry at temperatures <483 K and saturated vapour pressure <2 MPa. Variations in the intensity of X-ray diffraction reflections of both reactants and products provide quantitative information for studying the reaction kinetics of both dissolution and crystal growth. Feasibility is demonstrated by studying a cementitious mixture used for autoclaved aerated concrete production. During a period of 5.7 h at 466 K and 1.35 MPa, the crystallization of torbermorite and the partial consumption of quartz were monitored.

Kinetics of Multi-Step Redox Processes by Time-Resolved In Situ X-ray Diffraction

2016 ◽  
Vol 88 (11) ◽  
pp. 1684-1692 ◽  
Author(s):  
Lukas C. Buelens ◽  
Vladimir V. Galvita ◽  
Hilde Poelman ◽  
Christophe Detavernier ◽  
Guy B. Marin
Keyword(s):  
Redox Processes ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Kinetics Of

In situ high temperature X-ray diffraction study of the kinetics of phase separation in the uranium-plutonium mixed oxide (U0.55Pu0.45)O2-x

2014 ◽  
Vol 1645 ◽  
Author(s):  
Romain VAUCHY ◽  
Renaud.C. BELIN ◽  
Anne-Charlotte ROBISSON ◽  
Fiqiri HODAJ
Keyword(s):  
Phase Separation ◽  
Room Temperature ◽  
Mixed Oxides ◽  
Oxygen Stoichiometry ◽  
X Ray Diffraction ◽  
Fundamental Interest ◽  
X Ray ◽  
Uranium Plutonium ◽  
Kinetics Of

ABSTRACTUranium-plutonium mixed oxides incorporating high amounts of plutonium are considered for future nuclear reactors. For plutonium content higher than 20%, a phase separation occurs, depending on the temperature and on the oxygen stoichiometry. This phase separation phenomenon is still not precisely described, especially at high plutonium content. Here, using an original in situ fast X-ray diffraction device dedicated to radioactive materials, we evidenced a phase separation occurring during rapid cooling from 1773 K to room temperature at the rate of 0.05 and 2 K per second for a (U0.55Pu0.45)O2-x compound under a reducing atmosphere. The results show that the cooling rate does not impact the lattice parameters of the obtained phases at room temperature but their fraction. In addition to their obvious fundamental interest, these results are of utmost importance in the prospect of using uranium-plutonium mixed oxides with high plutonium content as nuclear fuels.

Grain-Growth Kinetics of Nanocrystalline Iron Studied In Situ by Synchrotron Real-Time X-ray Diffraction

2000 ◽  
Vol 104 (11) ◽  
pp. 2467-2476 ◽  
Author(s):  
H. Natter ◽  
M. Schmelzer ◽  
M.-S Löffler ◽  
C. E. Krill ◽  
A. Fitch ◽  
...  
Keyword(s):  
Real Time ◽  
Grain Growth ◽  
Growth Kinetics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nanocrystalline Iron ◽  
Grain Growth Kinetics ◽  
Kinetics Of
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