| 1. |
- Koskela, Salla, et al.
(författare)
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An Oxidative Enzyme Boosting Mechanical and Optical Performance of Densified Wood Films
- 2023
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Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 19:17
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Tidskriftsartikel (refereegranskat)abstract
- Nature has evolved elegant ways to alter the wood cell wall structure through carbohydrate-active enzymes, offering environmentally friendly solutions to tailor the microstructure of wood for high-performance materials. In this work, the cell wall structure of delignified wood is modified under mild reaction conditions using an oxidative enzyme, lytic polysaccharide monooxygenase (LPMO). LPMO oxidation results in nanofibrillation of cellulose microfibril bundles inside the wood cell wall, allowing densification of delignified wood under ambient conditions and low pressure into transparent anisotropic films. The enzymatic nanofibrillation facilitates microfibril fusion and enhances the adhesion between the adjacent wood fiber cells during densification process, thereby significantly improving the mechanical performance of the films in both longitudinal and transverse directions. These results improve the understanding of LPMO-induced microstructural changes in wood and offer an environmentally friendly alternative for harsh chemical treatments and energy-intensive densification processes thus representing a significant advance in sustainable production of high-performance wood-derived materials.
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| 2. |
- Mascher, Martin, et al.
(författare)
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A chromosome conformation capture ordered sequence of the barley genome
- 2017
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 544:7651, s. 427-433
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Tidskriftsartikel (refereegranskat)abstract
- Cereal grasses of the Triticeae tribe have been the major food source in temperate regions since the dawn of agriculture. Their large genomes are characterized by a high content of repetitive elements and large pericentromeric regions that are virtually devoid of meiotic recombination. Here we present a high-quality reference genome assembly for barley (Hordeum vulgare L.). We use chromosome conformation capture mapping to derive the linear order of sequences across the pericentromeric space and to investigate the spatial organization of chromatin in the nucleus at megabase resolution. The composition of genes and repetitive elements differs between distal and proximal regions. Gene family analyses reveal lineage-specific duplications of genes involved in the transport of nutrients to developing seeds and the mobilization of carbohydrates in grains. We demonstrate the importance of the barley reference sequence for breeding by inspecting the genomic partitioning of sequence variation in modern elite germplasm, highlighting regions vulnerable to genetic erosion.
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| 3. |
- Mastantuoni, Gabriella G.
(författare)
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Engineering of lignin in wood towards functional materials
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Through 270 million years of evolution, the finely tuned hierarchical structure of wood has been optimized for efficient nutrient transport and exceptional mechanical stability. Its distinctive orthotropic constitution can provide inspiration and design opportunities for the development of novel functional materials. In recent years, top-down modification approaches have adapted the wood structure for innovative applications, utilizing the hierarchical arrangement at different length scales. In doing so, preserving the structural integrity is of the essence.This thesis explores new top-down modification techniques for the functionalization and structural control of wood-based materials. With the intent of better preserving and utilizing the natural wood organization and native components, two different modification routes were explored on softwood Scots pine: complete lignin removal and in-situ lignin modification. Complete delignification was achieved through preventive crosslinking of the polysaccharide matrix, enhancing intercellular adhesion between tracheids and preventing the disintegration of the cellular arrangement after lignin removal. The second approach focused on chemical modification of lignin by sulfonation as an alternative to complete lignin removal, resulting in wood templates of high negative charge up to 375 µmol g-1 and with well-preserved residual lignin. Hot compression of the delignified wood veneers produced thin wood films with high optical transmittance of 71 % alongside exceptional tensile strength of 449 MPa and Young’s modulus of 50 GPa. Densification of lignin-retaining wood veneers yielded strong and transparent thin films with UV blocking ability. Additionally, these densified films could be easily recycled into discrete wood fibers. The integration of conductive polymers including poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and polypyrrole in in-situ sulfonated wood resulted in bio-composites with high conductivity up to 203 S m-1 and high pseudo-capacitance up to 38 mF cm-2, indicating that tailoring the wood chemistry and activating the redox activity of lignin by sulfonation are important strategies for the fabrication of composites with potential for sustainable energy applications. By tailoring both wood chemistry and morphology, a wood foam with unique microstructure, enhanced permeability, along with high ultimate strength of 9 MPa and Young’s modulus of 364 MPa was obtained. When combined with the conductive polymer PEDOT:PSS, the composite demonstrated uniform conductivity of 215 S m-1 and mechanoresponsive electrical resistance, showing promise in sensing and mechanoresponsive devices.Therefore, in-situ engineering of lignin proved to be a versatile toolkit to obtain wood templates of improved permeability and porosity, greater compliance to densification, and enhanced compatibility with conductive polymers.
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| 4. |
- Mastantuoni, Gabriella G., et al.
(författare)
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High-Strength and UV-Shielding Transparent Thin Films from Hot-Pressed Sulfonated Wood
- 2023
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Ingår i: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485.
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Tidskriftsartikel (refereegranskat)abstract
- Wood is a high-strength lightweight material owing to its orthotropic cellular structure and composite-like constitution. In conventional fabrication of wood-derived functional materials, the removal of the potentially beneficial components, such as lignin and hemicellulose, often leads to the disruption of the native hierarchical wood structure. Herein, we developed a facile method of in situ wood sulfonation followed by hot pressing for pine veneers to prepare high-density transparent thin films with preserved wood components and the natural fiber alignment. An optimum lignin content of the hot-pressed films was found to be 20.6% where both mechanical and optical properties were significantly enhanced with a more dense and compact structure. The hot-pressed transparent wood films also showed UV-blocking capability and could be recycled into discrete wood fibers owing to the sulfonate groups endowed by the in situ sulfonation step. The unique combination of properties achieved for thin wood films marks an important step in engineering functional wood-based materials that utilize both the structure of aligned fibers and the complex components of natural wood.
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| 5. |
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| 6. |
- Mastantuoni, Gabriella G., et al.
(författare)
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Rationally designed conductive wood with mechanoresponsive electrical resistance
- 2024
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Ingår i: Composites. Part A, Applied science and manufacturing. - : Elsevier BV. - 1359-835X .- 1878-5840. ; 178
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Tidskriftsartikel (refereegranskat)abstract
- Porous cellular foams, combining lightweight, high strength, and compressibility, hold great promise in a wide range of advanced applications. Here, the native structure of pine wood was modified by in-situ lignin sulfonation and unidirectional freezing, resulting in an alveolate structure inside the wood cell wall with arrays of sub-100 nm channels. The obtained wood foam exhibited highly enhanced permeability while retaining the native cellular arrangement and high lignin and hemicellulose content. Such engineered cellular foam contributed to superior mechanical performance with compressive strength of 9 MPa and Young's modulus of 344 MPa in the longitudinal direction. The high porosity allowed homogeneous infiltration of conductive polymer PEDOT:PSS inside the wood cell wall. The resulting composite exhibited high conductivity, sponge-like compressibility and the ability to modulate electrical resistance in a reversible manner in the radial direction. This rationally designed conductive wood demonstrated potential in durable and ultrasensitive pressure-responsive devices and strain sensors.
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| 7. |
- van Chinh, Tran, et al.
(författare)
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Utilizing native lignin as redox-active material in conductive wood for electronic and energy storage applications
- 2022
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 10:29, s. 15677-15688
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Tidskriftsartikel (refereegranskat)abstract
- Nanostructured wood veneer with added electroactive functionality combines structural and functional properties into eco-friendly, low-cost nanocomposites for electronics and energy technologies. Here, we report novel conducting polymer-impregnated wood veneer electrodes where the native lignin is preserved, but functionalized for redox activity and used as an active component. The resulting electrodes display a well-preserved structure, redox activity, and high conductivity. Wood samples were sodium sulfite-treated under neutral conditions at 165 °C, followed by the tailored distribution of PEDOT:PSS, not previously used for this purpose. The mild sulfite process introduces sulfonic acid groups inside the nanostructured cell wall, facilitating electrostatic interaction on a molecular level between the residual lignin and PEDOT. The electrodes exhibit a conductivity of up to 203 S m−1 and a specific pseudo-capacitance of up to 38 mF cm−2, with a capacitive contribution from PEDOT:PSS and a faradaic component originating from lignin. We also demonstrate an asymmetric wood pseudo-capacitor reaching a specific capacitance of 22.9 mF cm−2 at 1.2 mA cm−2 current density. This new wood composite design and preparation scheme will support the development of wood-based materials for use in electronics and energy storage.
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| 8. |
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| 9. |
- Wang, Shennan, Dr. 1992-, et al.
(författare)
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Wood xerogel for fabrication of high-performance transparent wood
- 2023
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Optically transparent wood has been fabricated by structure-retaining delignification of wood and subsequent infiltration of thermo- or photocurable polymer resins but still limited by the intrinsic low mesopore volume of the delignified wood. Here we report a facile approach to fabricate strong transparent wood composites using the wood xerogel which allows solvent-free infiltration of resin monomers into the wood cell wall under ambient conditions. The wood xerogel with high specific surface area (260 m2 g–1) and high mesopore volume (0.37 cm3 g–1) is prepared by evaporative drying of delignified wood comprising fibrillated cell walls at ambient pressure. The mesoporous wood xerogel is compressible in the transverse direction and provides precise control of the microstructure, wood volume fraction, and mechanical properties for the transparent wood composites without compromising the optical transmittance. Transparent wood composites of large size and high wood volume fraction (50%) are successfully prepared, demonstrating potential scalability of the method.
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| 10. |
- Wu, Ya-ting, et al.
(författare)
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Selective and simultaneous determination of trace bisphenol A and tebuconazole in vegetable and juice samples by membrane-based molecularly imprinted solid-phase extraction and HPLC
- 2014
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Ingår i: Food Chemistry. - : Elsevier BV. - 1873-7072 .- 0308-8146. ; 164, s. 527-535
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Tidskriftsartikel (refereegranskat)abstract
- Nanofibrous molecularly imprinted membranes (nano-MIMs) with multi-analyte selectivity were prepared by encapsulating two types of molecularly imprinted polymer nanoparticles (MIP-NPs) into electrospun polyvinyl alcohol nanofibers. The obtained nano-MIMs maintained high molecular selectivity offered by each of the MIP-NPs. Nano-MIM embedding BPA-imprinted nanoparticles and TBZ-imprinted nanoparticles together showed the highest binding selectivity for acid bisphenol A (BPA) and basic tebuconazole (TBZ). This nano-MIM was used as affinity material of membrane-based molecularly imprinted solid-phase extraction (m-MISPE) to extract trace BPA and TBZ in vegetables and juices simultaneously. The recoveries of BPA and TBZ from different samples were higher than 70.33% with RSDs lower than 9.57%. m-MISPE gave better HPLC separation efficiencies and higher recoveries than conventional SPE based on C18/SCX. Multi-analyte selective m-MISPE combined with HPLC realized selective and simultaneous determination of several trace analytes with opposite charges/polarities in different food samples. (C) 2014 Elsevier Ltd. All rights reserved.
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