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Carbon-13 NMR chemical-shift imaging study of dewatering of green sapwood by cycling carbon dioxide between the supercritical fluid and gas phases
•Partly dewatered sapwood was immersed in supercritical carbon dioxide.•Carbon-13 chemical-shift imaging mapped the distribution of carbon dioxide.•Carbon dioxide concentrations were relatively high in latewood bands.•Sap-filled cell lumens in earlywood hindered penetration by carbon dioxide. Carbon...
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Published in: | The Journal of supercritical fluids 2014-11, Vol.95, p.535-540 |
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Main Authors: | , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | •Partly dewatered sapwood was immersed in supercritical carbon dioxide.•Carbon-13 chemical-shift imaging mapped the distribution of carbon dioxide.•Carbon dioxide concentrations were relatively high in latewood bands.•Sap-filled cell lumens in earlywood hindered penetration by carbon dioxide.
Carbon-13 chemical-shift imaging (CSI) was used to study the distribution of CO2 in green pine sapwood that was partially dewatered by a process in which CO2 was cycled between the supercritical fluid and gas phases. Proton magnetic resonance imaging (MRI) was used to characterise the corresponding distribution of water. The CSI experiment showed strongest signals from cells with weakest proton MRI signals. This was consistent with a mechanism in which latewood bands provide pathways for supercritical CO2 to penetrate into the interior of a specimen. Supercritical CO2 also penetrated earlywood exposed on surfaces of the specimen. |
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ISSN: | 0896-8446 1872-8162 |
DOI: | 10.1016/j.supflu.2014.08.026 |