Rotorua, New Zealand
Rotorua, New Zealand

Time filter

Source Type

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.


Franich R.A.,Scion Research | Franich R.A.,Chemipreneur Ltd | Gallagher S.,Scion Research | Kroese H.,Scion Research
Journal of Supercritical Fluids | Year: 2014

Green radiata pine sapwood was dewatered through exposure to CO 2, cyclically alternated between supercritical fluid and gas phase. Plots of moisture content against cycle number showed sigmoidal shapes, with the maximum slope showing a linear dependence on the maximum pressure applied in each cycle, over the range 8-20 MPa. The initial slope varied as the square root of the hold time at 40 MPa, as expected for diffusion of CO2 through water into the wood. The temperature of the vessel showed no influence on the dewatering rate over the range 38-58 °C. Dissection of partly-dewatered specimens showed strong moisture gradients in green wood, changing to a relatively uniform distribution through a cross-section as the moisture content decreased to an end-point of 40% of the oven-dry weight. This end-point was attributed to moisture remaining in cell walls, after the lumens had been emptied. © 2014 Elsevier B.V.


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.


Behr V.C.,University of Würzburg | 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.


Donaldson L.A.,Scion Research | Kroese H.W.,Scion Research | Hill S.J.,Scion Research | Franich R.A.,Scion Research | Franich R.A.,Chemipreneur Ltd
Journal of Microscopy | Year: 2015

A novel approach to nanoscale detection of cell wall porosity using confocal fluorescence microscopy is described. Infiltration of cell walls with a range of nitrophenyl-substituted carbohydrates of different molecular weights was assessed by measuring changes in the intensity of lignin fluorescence, in response to the quenching effect of the 4-nitrophenyl group. The following carbohydrates were used in order of increasing molecular weight; 4-nitrophenyl β-D-glucopyrano-side (monosaccharide), 4-nitrophenyl β-D-lactopyranoside (disaccharide), 2-chloro-4-nitrophenyl β-D-maltotrioside (trisaccharide), and 4-nitrophenyl α-D-maltopentaoside (pentasaccharide). This technique was used to compare cell wall porosity in wood which had been dewatered to 40% moisture content using supercritical CO2, where cell walls remain fully hydrated, with kiln dried wood equilibrated to 12% moisture content. Infiltration of cell walls as measured by fluorescence quenching, was found to decrease with increasing molecular weight, with the pentasaccharide being significantly excluded compared to the monosaccharide. Porosity experiments were performed on blocks and sections to assess differences in cell wall accessibility. Dewatered and kiln dried wood infiltrated as blocks showed similar results, but greater infiltration was achieved by using sections, indicating that not all pores were easily accessible by infiltration from the lumen surface. In wood blocks infiltrated with 4-nitrophenyl α-D-maltopentaoside, quenching of the secondary wall was quite variable, especially in kiln dried wood, indicating limited connectivity of pores accessible from the lumen surface. Lay Description: The subject of this paper is the detection of very small pores in wood. These pores are important for various modification processes that might be involved in making wood resistant to decay, improving the hardness of wood or reducing shrinkage of wood during drying. Pores in the cell walls of wood fibres are too small to see directly with a microscope but they can be better detected by infiltrating with dyes. Because many dye molecules are too large to fit inside the very small wood pores, we have developed an alternative approach where we use small colourless sugar molecules that change the natural fluorescence of the wood when the molecules infiltrate the pores. By using molecules of different sizes, we are able to measure the approximate size and the location of the pores and hence get an idea about what constraints may be involved in modifying wood with chemicals. This method may have applications to study the porosity of other types of materials. Journal compilation © 2015 Royal Microscopical Society.


Behr V.C.,University of Würzburg | Schmid M.W.,University of Würzburg | 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.


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 Würzburg
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.

Loading Chemipreneur Ltd collaborators
Loading Chemipreneur Ltd collaborators