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.

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.

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.

The water vapour sorption behaviour of acetylated birch wood: how acetylation affects the sorption isotherm and accessible hydroxyl content

2013 ◽  
Vol 49 (5) ◽  
pp. 2362-2371 ◽  
Author(s):  
Carmen-Mihaela Popescu ◽  
Callum A. S. Hill ◽  
Simon Curling ◽  
Graham Ormondroyd ◽  
Yanjun Xie
Keyword(s):  
Water Vapour ◽  
Sorption Isotherm ◽  
Birch Wood ◽  
Hydroxyl Content ◽  
Sorption Behaviour ◽  
Water Vapour Sorption ◽  
Vapour Sorption

Thermodynamic analysis of water vapour sorption behaviour of juvenile and mature wood of Abies alba Mill.

2015 ◽  
Vol 50 (22) ◽  
pp. 7282-7292 ◽  
Author(s):  
Cristina Simón ◽  
Luis García Esteban ◽  
Paloma de Palacios ◽  
Francisco García Fernández ◽  
Raquel Martín-Sampedro ◽  
...  
Keyword(s):  
Water Vapour ◽  
Thermodynamic Analysis ◽  
Abies Alba ◽  
Mature Wood ◽  
Sorption Behaviour ◽  
Water Vapour Sorption ◽  
Vapour Sorption

scholarly journals Water Vapour Sorption and Moisture Transport in and Across Fibre Direction of Wood

2021 ◽  
Author(s):  
Alexander Murr
Keyword(s):  
Relative Humidity ◽  
Water Vapour ◽  
Sorption Kinetics ◽  
Sample Thickness ◽  
Fibre Direction ◽  
Transient Conditions ◽  
Water Vapour Sorption ◽  
Vapour Sorption ◽  
Water Vapour Diffusion ◽  
The Impact

Abstract Water vapour sorption experiments are frequently used to characterise the absorption and desorption of water in wood during transient conditions in relative humidity. When interpreting such experiments, it is still unclear to what extend the resulting time-dependent change of sample mass (i.e. sorption kinetics) is influenced by moisture transport, sorption and sorption related processes. To evaluate the impact of water vapour diffusion under such transient conditions, this study investigates the sorption kinetics of small wood samples with different lengths of transport pathways in and across fibre direction. For this purpose, water vapour sorption experiments on Norway spruce ( Picea abies ) samples were performed under identical climatic conditions at ambient air pressure and ambient standard temperature. The results showed that sample thickness has an impact on the sorption kinetics along the whole tested range of relative humidity. Differences between the sorption kinetics for samples in and across fibre direction were considerable at low relative humidity, indicating the relevance of water vapour diffusion through the lumen-pit-ray system. In contrast at high relative humidity, differences between the sorption kinetics for samples in and across fibre direction started to disappear while the impact of sample thickness was still considerable. Therefore, it seems as if an additional or modified process that depends on the number of sorption sites becomes relevant at an increased moisture content of wood. This process, as well as the increasing uptake and release of water across fibre direction, should be further investigated to gain a better understanding of the absorption and desorption of water in wood.

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