An ecofriendly approach was developed for preparing copper-doped carbon dots (CDs) with superior ... more 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...
We investigated the effects of polymer blend variation on the physical, mechanical, and thermal p... more We investigated the effects of polymer blend variation on the physical, mechanical, and thermal properties of wood-polymer composites (WPC). We used high-density polyethylene (HDPE) and polypropylene (PP) and a combination of 80% PP, 20% HDPE, and 80% HDPE, 20% PP as polymer blends for WPC formulations to simulate recycled plastics. We used black spruce (Picea mariana Mill.) hammer milled fibers (75–250 μm) at 35 wt% as a filler for all the formulations. A two-step process was used for WPC manufacturing; pellet extrusion followed by test samples injection. Tensile and three bending tests characterized the WPC mechanical properties. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) characterized the WPCs’ thermal properties. Water absorption and contact angle measurements assessed the composite dimensional stability. Infrared spectroscopy (FTIR) and electron scanning microscopy (SEM) investigated the WPCs’ surface chemistry and microstructure. Mechanical pr...
This study aims to investigate the feasibility of producing OSB from softwood species used in the... more This study aims to investigate the feasibility of producing OSB from softwood species used in the Eastern Canadian softwood lumber industry in the context of the overcapacity of softwood chips traditionally produced for the pulp and paper industry. Balsam fir, black spruce, and jack pine logs were used to make 15 mm thick OSB panels with a target density of 600 kg/m3. The panels were manufactured at a temperature of 210 °C during a pressing cycle of 300 s. Strands with different thicknesses were used to obtain a constant specific surface of 6.7 m2/kg for the three species. The bending modulus of the rupture and modulus of elasticity, internal bond, and thickness swelling of the OSB panels were determined and compared to the CSA standard requirements. The species significantly affected the physical and mechanical properties of OSB. The bending properties of OSB decreased with an increase in the species wood density. The internal bond strength of OSB increased with the increase in spe...
Flavia Lega Braghiroli, Research Forest Institute (RFI), University of Québec in Abitibi-Témiscam... more Flavia Lega Braghiroli, Research Forest Institute (RFI), University of Québec in Abitibi-Témiscamingue (UQAT), 445 Boul. de l’Université, Rouyn-Noranda, Québec, QC J9X 5E4, Canada flavia.braghiroli@uqat.ca; flavia.braghiroli@cegepat.qc.ca Hassine Bouafif, Technology Center for Industrial Waste (CTRI), Cégep de l’Abitibi-Témiscamingue (College of Abitibi-Témiscamingue), 425 Boul. du Collège Rouyn-Noranda, QC J9X 5E5, Canada Carmen Mihaela Neculita, Research Institute on Mines and the Environment (RIME), University of Québec in Abitibi-Témiscamingue (UQAT), 445 Boul. de l’Université, Rouyn-Noranda, QC J9X 5E4, Canada Ahmed Koubaa, Research Forest Institute (RFI), University of Québec in Abitibi-Témiscamingue (UQAT), 445 Boul. de l’Université, Rouyn-Noranda, Québec, QC J9X 5E4, Canada
Abstract The project aims to develop cellulose in new biocomposites to produce dielectric materia... more Abstract The project aims to develop cellulose in new biocomposites to produce dielectric materials based on thermoplastic matrices. Cellulose fibers bring multiple advantages to thermoplastic matrices in mechanical, physicochemical, thermal, and dielectric properties. Although these biocomposites are known for their advanced mechanical properties, only a few studies investigated their dielectric behavior and the effect of cellulose fibers on these properties. The bio-based composites must have better dielectric properties and excellent ductility to use as insulators in electrical cables. Thus, we investigated the dielectric properties (dielectric constant (e’), loss factor (e’’), conductivity (σ) and resistivity (ρ)) of high-density polyethylene (HDPE) and cellulose fibers composites. Results prove that the addition of cellulosic fibers increased the dielectric constant, the loss factor, and the conductivity of the materials compared to the neat polymer. Composites with 50 wt% fiber content showed the highest values. Therefore, the volume resistivity of all the composites studied decreased with frequency and fiber content. In addition, the reinforced polymer exhibited an intermediate thermal behavior between the polymer and the fibers. Thus, they are thermally stable materials up to 320 °C.
Abstract The aim of this study was to improve performance of a vegetable oil-based coating with a... more Abstract The aim of this study was to improve performance of a vegetable oil-based coating with addition of nanoparticles. Uniform distribution of added nanoclay, nanosilica and nanoalumina is the key to ensure the increased abrasion resistance. A high speed mixer, bead mill and ultrasonic mixer were used to disperse the nanoparticles into coatings. The quality of nanoparticle dispersion in liquid coating was studied by dynamic light scattering (DLS), and in dry film by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Using a high-speed mixer with addition of glass beads resulted in exceptional dispersion of nanoparticles in coating as confirmed by the above techniques. Although, addition of nanoclay had a positive effect on drying time of coating (reducing it by 37%), it had negative effects on viscosity (increasing it by 5 times). Overall, addition of 1% nanoparticles significantly increased the abrasion resistance of modified coating after 2000 abrasion cycles in comparison with pure unmodified coatings as applied on larch wood flooring samples.
Chromated copper arsenate-treated (cca) wood disposal faces environmental restrictions due to its... more Chromated copper arsenate-treated (cca) wood disposal faces environmental restrictions due to its toxicity, heavy metal leaching in storage sites, and greenhouse gas emissions during incineration. Thus, finding new management methods for this contaminated wood at the end of life is crucial. This study evaluated the effect of pyrolysis temperature (300, 400, and 500 °C), particle size, biochar yield, and the behavior of arsenic (As), chromium (Cr), and copper (Cu) during treated-wood pyrolysis. The highest biochar yield was obtained at 300 °C for fine particles. The biochar retention of heavy metals decreased with increasing pyrolysis temperature. At 300 °C, the highest biochar As, Cr, and Cu retentions were 76, 91, and 83%. At 500 °C, biochar only retained 43% of the As. Additionally, heavy metal leaching from the biochar exceeded the Environmental Protection Agency’s (EPA) maximum concentration limit of 5 mg/L. High-density polyethylene encapsulation of contaminated biochar reduced...
The flame retardancy of wood–polymer composites significantly affects their potential application... more The flame retardancy of wood–polymer composites significantly affects their potential applications. Thus, multilayered wood flour/high-density polyethylene (HDPE)/polycarbonate (PC) composites were prepared via thermocompression to improve the fire retardancy of wood–polymer composites in this paper. Thermal degradation behavior, flame retardancy, and flexural strengths of the resulting composites were investigated using a thermogravimetric analysis, cone calorimetry, and mechanical testing machine, respectively. Results revealed that the boric acid treatment reduced the heat release rate and total heat release of the wood flour/HDPE composites and increased their mass of residues. However, boric acid reduced the flexural strength of the resulting composites. The combustion test indicated that PC cap layers suppressed the combustion of the resulting composites via the formation of carbon layers. Adding PC layers reduced heat release and increased the flexural strength of the resulti...
An ecofriendly approach was developed for preparing copper-doped carbon dots (CDs) with superior ... more 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...
We investigated the effects of polymer blend variation on the physical, mechanical, and thermal p... more We investigated the effects of polymer blend variation on the physical, mechanical, and thermal properties of wood-polymer composites (WPC). We used high-density polyethylene (HDPE) and polypropylene (PP) and a combination of 80% PP, 20% HDPE, and 80% HDPE, 20% PP as polymer blends for WPC formulations to simulate recycled plastics. We used black spruce (Picea mariana Mill.) hammer milled fibers (75–250 μm) at 35 wt% as a filler for all the formulations. A two-step process was used for WPC manufacturing; pellet extrusion followed by test samples injection. Tensile and three bending tests characterized the WPC mechanical properties. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) characterized the WPCs’ thermal properties. Water absorption and contact angle measurements assessed the composite dimensional stability. Infrared spectroscopy (FTIR) and electron scanning microscopy (SEM) investigated the WPCs’ surface chemistry and microstructure. Mechanical pr...
This study aims to investigate the feasibility of producing OSB from softwood species used in the... more This study aims to investigate the feasibility of producing OSB from softwood species used in the Eastern Canadian softwood lumber industry in the context of the overcapacity of softwood chips traditionally produced for the pulp and paper industry. Balsam fir, black spruce, and jack pine logs were used to make 15 mm thick OSB panels with a target density of 600 kg/m3. The panels were manufactured at a temperature of 210 °C during a pressing cycle of 300 s. Strands with different thicknesses were used to obtain a constant specific surface of 6.7 m2/kg for the three species. The bending modulus of the rupture and modulus of elasticity, internal bond, and thickness swelling of the OSB panels were determined and compared to the CSA standard requirements. The species significantly affected the physical and mechanical properties of OSB. The bending properties of OSB decreased with an increase in the species wood density. The internal bond strength of OSB increased with the increase in spe...
Flavia Lega Braghiroli, Research Forest Institute (RFI), University of Québec in Abitibi-Témiscam... more Flavia Lega Braghiroli, Research Forest Institute (RFI), University of Québec in Abitibi-Témiscamingue (UQAT), 445 Boul. de l’Université, Rouyn-Noranda, Québec, QC J9X 5E4, Canada flavia.braghiroli@uqat.ca; flavia.braghiroli@cegepat.qc.ca Hassine Bouafif, Technology Center for Industrial Waste (CTRI), Cégep de l’Abitibi-Témiscamingue (College of Abitibi-Témiscamingue), 425 Boul. du Collège Rouyn-Noranda, QC J9X 5E5, Canada Carmen Mihaela Neculita, Research Institute on Mines and the Environment (RIME), University of Québec in Abitibi-Témiscamingue (UQAT), 445 Boul. de l’Université, Rouyn-Noranda, QC J9X 5E4, Canada Ahmed Koubaa, Research Forest Institute (RFI), University of Québec in Abitibi-Témiscamingue (UQAT), 445 Boul. de l’Université, Rouyn-Noranda, Québec, QC J9X 5E4, Canada
Abstract The project aims to develop cellulose in new biocomposites to produce dielectric materia... more Abstract The project aims to develop cellulose in new biocomposites to produce dielectric materials based on thermoplastic matrices. Cellulose fibers bring multiple advantages to thermoplastic matrices in mechanical, physicochemical, thermal, and dielectric properties. Although these biocomposites are known for their advanced mechanical properties, only a few studies investigated their dielectric behavior and the effect of cellulose fibers on these properties. The bio-based composites must have better dielectric properties and excellent ductility to use as insulators in electrical cables. Thus, we investigated the dielectric properties (dielectric constant (e’), loss factor (e’’), conductivity (σ) and resistivity (ρ)) of high-density polyethylene (HDPE) and cellulose fibers composites. Results prove that the addition of cellulosic fibers increased the dielectric constant, the loss factor, and the conductivity of the materials compared to the neat polymer. Composites with 50 wt% fiber content showed the highest values. Therefore, the volume resistivity of all the composites studied decreased with frequency and fiber content. In addition, the reinforced polymer exhibited an intermediate thermal behavior between the polymer and the fibers. Thus, they are thermally stable materials up to 320 °C.
Abstract The aim of this study was to improve performance of a vegetable oil-based coating with a... more Abstract The aim of this study was to improve performance of a vegetable oil-based coating with addition of nanoparticles. Uniform distribution of added nanoclay, nanosilica and nanoalumina is the key to ensure the increased abrasion resistance. A high speed mixer, bead mill and ultrasonic mixer were used to disperse the nanoparticles into coatings. The quality of nanoparticle dispersion in liquid coating was studied by dynamic light scattering (DLS), and in dry film by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Using a high-speed mixer with addition of glass beads resulted in exceptional dispersion of nanoparticles in coating as confirmed by the above techniques. Although, addition of nanoclay had a positive effect on drying time of coating (reducing it by 37%), it had negative effects on viscosity (increasing it by 5 times). Overall, addition of 1% nanoparticles significantly increased the abrasion resistance of modified coating after 2000 abrasion cycles in comparison with pure unmodified coatings as applied on larch wood flooring samples.
Chromated copper arsenate-treated (cca) wood disposal faces environmental restrictions due to its... more Chromated copper arsenate-treated (cca) wood disposal faces environmental restrictions due to its toxicity, heavy metal leaching in storage sites, and greenhouse gas emissions during incineration. Thus, finding new management methods for this contaminated wood at the end of life is crucial. This study evaluated the effect of pyrolysis temperature (300, 400, and 500 °C), particle size, biochar yield, and the behavior of arsenic (As), chromium (Cr), and copper (Cu) during treated-wood pyrolysis. The highest biochar yield was obtained at 300 °C for fine particles. The biochar retention of heavy metals decreased with increasing pyrolysis temperature. At 300 °C, the highest biochar As, Cr, and Cu retentions were 76, 91, and 83%. At 500 °C, biochar only retained 43% of the As. Additionally, heavy metal leaching from the biochar exceeded the Environmental Protection Agency’s (EPA) maximum concentration limit of 5 mg/L. High-density polyethylene encapsulation of contaminated biochar reduced...
The flame retardancy of wood–polymer composites significantly affects their potential application... more The flame retardancy of wood–polymer composites significantly affects their potential applications. Thus, multilayered wood flour/high-density polyethylene (HDPE)/polycarbonate (PC) composites were prepared via thermocompression to improve the fire retardancy of wood–polymer composites in this paper. Thermal degradation behavior, flame retardancy, and flexural strengths of the resulting composites were investigated using a thermogravimetric analysis, cone calorimetry, and mechanical testing machine, respectively. Results revealed that the boric acid treatment reduced the heat release rate and total heat release of the wood flour/HDPE composites and increased their mass of residues. However, boric acid reduced the flexural strength of the resulting composites. The combustion test indicated that PC cap layers suppressed the combustion of the resulting composites via the formation of carbon layers. Adding PC layers reduced heat release and increased the flexural strength of the resulti...
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