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An ecofriendly approach was developed for preparing copper-doped carbon dots (CDs) with superior photocatalysis using chromium-copper-arsenic (CCA)-treated wood waste as a precursor. Original wood (W-CDs), CCA-treated wood (C-CDs), and bioremediation CCA wood (Y-CDs) were used as the precursors. The chemical composition and structural, morphological, and optical properties, as well as the photocatalytic ability of the synthesized CDs varied with wood type. The C-CDs and W-CDs had similar characteristics: quasispherical in shape and with a diameter of 2 to 4.5 nm. However, the Y-CDs particles were irregular and stacked together, with a size of 1.5–3 nm. The presence of nitrogen prevented the formation of an aromatic structure for those CDs fabricated from bioremediation CCA wood. The three synthesized CDs showed a broad absorption peak at 260 nm and a weak absorption peak at 320 nm. Proof of the model study for the fabrication of luminescent CDs from CCA wood waste for bioimaging was provided. The degradation rate of CD photocatalytic MB was 97.8% for 30 min. Copper doping gives the CDs electron acceptor properties, improving their photocatalytic efficiency. This study provides novel ways to prepare nanomaterials from decommissioned wood as a nontoxic and low-cost alternative to fluorescent dots. [ABSTRACT FROM AUTHOR]

Delignified wood (DW) was prepared from fast-growing poplar wood by delignification with a formic acid–water azeotropic system. Compressed wood (CW) was then obtained through a mechanical hot-pressing process. The effects of the delignification degree on the physical strength of the CW were studied. To further promote the strength of the wood, a new approach was proposed by embedding cellulose nanocrystals (CNCs) into DW followed by densification and producing the reinforced wood (RW). Here, CNCs were embedded in the wood, leading to reduced water uptake and remarkably enhanced dimensional stability, as well as generally improved mechanical properties. The test on the mechanical properties exhibited a significant improvement for the RW in contrast with the CW with maximum vickers hardness value (HV), flexural strength, tensile strength, and tensile elastic modulus of 800, 211 MPa, 183 MPa, and 14 GPa, which were increased by 12%, 22%, 11%, and 16%, respectively, compared to the CW. These results demonstrate that CNC is a promising enhancer to intensify the strength of wood. This work not only provides an effective and green approach to producing high-performance materials from fast-growing wood, but also improves the mechanical properties of wood without the introduction of heterocomponents. The delignified wood (DW) was prepared using formic acid–water azeotropic system, and the degradation degrees of wood cellulose were further investigated by controlling the degree of delignification. Based on the preparation method of the compress wood (CW), the reinforced wood (RW) was obtained by combining delignification, embedding CNC and followed by densification. [ABSTRACT FROM AUTHOR]

Developments in 3D printing and CT scanning technologies have facilitated the imitation of natural wood structures. However, creating composites from the elementary features of anisotropic wood structures remains a new frontier. This paper aims to investigate the potential of constructing and 3D printing mechanically customizable composites by combining anisotropic elementary models reconstructed from the micro X-ray computed tomography (μ-CT) scanning of wood. In this study, an arbitrary region of interest selected from the μ-CT scanning of a sample of Manchurian walnut (Juglans mandshurica) was reconstructed into isosurfaces that constituted the 3D model of an elementary model. Elementary models were combined to form the wood-inspired composites in various arrangements. The surface and interior structures of the elementary model were found to be customizable through adjusting the image Threshold and Surface Quality Factors during 3D volume reconstruction. Compressional simulations and experiments performed on the elementary model (digital and 3D printed) revealed that its compressive behavior was wood-like and anisotropic. Numerical analysis established a preliminary link between the arrangements of elementary models and the compressive stiffness of respective composites, showing that it is possible to control the compressive behaviors of the composites through the design of specific elementary model arrangements. [ABSTRACT FROM AUTHOR]

Oriented strandboards were constructed from various combinations of mixed hardwood flakes. Fractal dimension of void size (FDVS) in the manufactured samples was studied by means of X-ray computer tomography images and a computer image processing technique. The FDVS value was high in the panel surface layers and decreased toward the panel center, and the FDVS decrement was linear to increased porosity. At the same overall porosity level, the FDVS varied as function of void distribution. FDVS could be a useful additional parameter for characterizing the internal void structure of strand-based wood composites. [ABSTRACT FROM AUTHOR]

Demand for high-performance biocomposites is increasing due to their ease of processing, low environmental impact, and in-service performance. This study investigated the effect of boric acid modification of wood flour on polycarbonate (PC) wood composites' thermal stability, fire retardancy, water absorption, and creep behavior. The composites' fire retardancy increased with increasing wood flour content, and their char residue increased by 102.3% compared to that of pure PC. However, the water absorption of the resulting composites increased due to the hydroxyl groups of the wood flour. Wood flour also improved the composites' anti-creep properties. The excellent fire retardancy and anti-creep properties of wood–PC composites expand their use in the construction sector. [ABSTRACT FROM AUTHOR]