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Rotorua, New Zealand

Behr V.C.,University of Wurzburg | Schmid M.W.,University of Wurzburg | Franich R.A.,Scion Research | Franich R.A.,Chemipreneur Ltd | Meder R.,CSIRO
Concepts in Magnetic Resonance Part B: Magnetic Resonance Engineering | Year: 2013

Nuclear magnetic resonance spectroscopy and imaging are well-established tools in chemistry, physics, and life sciences. Nevertheless, most applications are performed at room temperature and atmospheric pressure. To study the processes in supercritical fluids, sample containers and coils have to be redesigned to especially allow for higher pressures up to several hundred times the atmospheric pressure. In this study, we present a setup for performing spectroscopic and imaging experiments on wood immersed in supercritical CO2 at up to 20 MPa for drying. A magnetic resonance-compatible autoclave as well as a double-tuned 1H/13C-birdcage coil was designed and a setup for regulating pressure and storing gases was assembled. We were able to successfully perform measurements on the wood and water during the drying process and gaininsights into the displacement of water and its chemical reactions with the highly pressurized CO2. © 2013 Wiley Periodicals, Inc.

Herold N.,Eberswalde University for Sustainable Development | Grigsby W.J.,Scion Research | Franich R.A.,Chemipreneur Ltd | Pfriem A.,Eberswalde University for Sustainable Development
European Journal of Wood and Wood Products | Year: 2015

Dynamic mechanical thermal analysis has been used to monitor the change in wood veneer stiffness due to furfuryl alcohol impregnation and plasticization of wood components and subsequent polymerization of furfuryl alcohol within wood material. This explains the improvement in the moulding ability of wood veneer where furfuryl alcohol aids in wood plasticization, and the increase in moulded shape stability achieved when furfuryl alcohol is polymerised within wood cell walls. © 2015, Springer-Verlag Berlin Heidelberg.

Herold N.,Eberswalde University Of Applied Sciences | Dietrich T.,TU Dresden | Grigsby W.J.,Scion Research | Franich R.A.,Chemipreneur Ltd | And 3 more authors.
BioResources | Year: 2013

The polymerization kinetics of furfuryl alcohol in wood veneer were studied using differential scanning calorimetry (DSC) and were compared with weight gains of treated wood veneers. Maleic anhydride was used as the reaction initiator. DSC data were obtained for samples of the veneers that had been impregnated with neat furfuryl alcohol or with furfuryl alcohol diluted with ethanol, and using two ratios of maleic anhydride to furfuryl alcohol. The high ratio of maleic anhydride to furfuryl alcohol (1:9) favoured rapid polymerization at a lower temperature, whereas the lower ratio (1:19) resulted in a relatively slower rate of polymerization, which required higher temperatures to affect the reaction. A higher temperature also led to an increase in furfuryl alcohol evaporation from the prepared veneers. The DSC data was compared with data obtained from furfuryl alcohol impregnated wood veneers but without the addition of maleic anhydride. DSC data is in good agreement with weight percentage gains (WPGs) obtained for samples impregnated with differently composed solutions. While higher maleic anhydride contents led to higher WPGs, ethanol dilution inhibits polymer formation, resulting in lower WPG.

Meder R.,CSIRO | Franich R.A.,Scion Research | Franich R.A.,Chemipreneur Ltd | Callaghan P.T.,Victoria University of Wellington | Behr V.C.,University of Wurzburg
Holzforschung | Year: 2015

A comparison of moisture loss from Pinus radiata sapwood by conventional forced air-drying and a novel supercritical carbon dioxide (scCO2) dewatering process has been examined in situ using magnetic resonance microimaging. Air-drying results in the nonuniform removal of moisture within the wood volume, leading to a dry core and wet perimeter where water evaporated, whereas the scCO2 dewatering process resulted in moisture expulsion more uniformly throughout the volume of the specimen, especially so within the earlywood. © 2015 by De Gruyter.

Behr V.C.,University of Wurzburg | Hill S.J.,Scion Research | Meder R.,CSIRO | Sandquist D.,Scion Research | And 3 more authors.
Journal of Supercritical Fluids | Year: 2014

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. © 2014 Elsevier B.V. All rights reserved.

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