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Yu Pu Deng

Bio: Yu Pu Deng is an academic researcher from Beijing Forestry University. The author has contributed to research in topics: Materials science & Ultimate tensile strength. The author has co-authored 1 publications.

Papers
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Journal ArticleDOI
TL;DR: In this paper , an atmospheric dielectric barrier discharge (DBD) plasma treatment was used to modify the interfacial properties of heat-treated wood (HTW), such as the microstructure, chemical structure, and wettability.
Abstract: Abstract The present study used an atmospheric dielectric barrier discharge (DBD) plasma treatment to modify the interfacial properties of heat-treated wood (HTW). The changes in the wood surface characteristics, such as the microstructure, chemical structure, and wettability, were investigated using scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), Fourier-transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Further, the fluorescent tracer technique was used to analyze the effect of plasma treatment on the adhesive penetration inwood. Results showed that the wettability of water and phenol-formaldehyde adhesives on the surface of HTW significantly improved after plasma treatment due to the increase in the hydrophilic and oxygen-containing functional groups. The average penetration (AP) and effective penetration (EP) of the phenolic adhesive into HTW also increased significantly after plasma treatment; the AP value of the E-E (earlywood bound to earlywood) HTW samples increased from 909 to 1674 μm, and the EP value from 60 to 183 μm upon plasma treatment. These observations indicate that the DBD plasma treatment is a promising method to improve the bonding properties of the glued HTW products.

3 citations

Journal ArticleDOI
10 Mar 2023-Small
TL;DR: In this article , a microstructure design strategy for dispersing CoPc molecules on a carbon substrate for efficient CO2 transport during CO2 electrolysis is proposed and demonstrated.
Abstract: Cobalt phthalocyanine (CoPc) has attracted particular interest owing to its excellent activity during the electrochemical CO2 conversion to CO. However, the efficient utilization of CoPc at industrially relevant current densities is still a challenge owing to its nonconductive property, agglomeration, and unfavorable conductive substrate design. Here, a microstructure design strategy for dispersing CoPc molecules on a carbon substrate for efficient CO2 transport during CO2 electrolysis is proposed and demonstrated. The highly dispersed CoPc is loaded on a macroporous hollow nanocarbon sheet to act as the catalyst (CoPc/CS). The unique interconnected and macroporous structure of the carbon sheet forms a large specific surface area to anchor CoPc with high dispersion and simultaneously boosts the mass transport of reactants in the catalyst layer, significantly improving the electrochemical performance. By employing a zero-gap flow cell, the designed catalyst can mediate CO2 to CO with a high full-cell energy efficiency of 57% at 200 mA cm-2 .

1 citations

Journal ArticleDOI
12 Feb 2023-Forests
TL;DR: In this article , changes in mechanical properties, crystallinity index, and DSC characteristics of PLA/coffee grounds with different dosages were analyzed by XRD, DSC, and mechanical property tests.
Abstract: Coffee is one of the most popular beverages in the world. It generates a waste known as coffee grounds. In this work, changes in mechanical properties, crystallinity index, and DSC characteristics of PLA/coffee grounds with different dosages were analyzed by XRD, DSC, and mechanical property tests. Statistical analysis showed that the modulus of rupture of PLA/coffee grounds 3D printing materials was maximal at 109.07 MPa and 3604 MPa when 3% coffee grounds were added. The tensile strength of the untreated PLA complex was 49.99 MPa, and the tensile strength increased from 49.99 MPa to 51.28 MPa after 3% coffee grounds were added. However, there was no significant difference between the PLA complex and PLA/coffee grounds 3D printing materials when the additions were lower than 3%. The statistical analysis showed that when the coffee grounds additions increased from 5% to 7%, the tensile strength of PLA/coffee grounds 3D printing products significantly decreased. For example, the tensile strength decreased from 49.99 MPa to 26.45 MPa with addition of 7% coffee grounds. The difference between the glass transition, cold crystallization, and melting temperatures of PLA coffee grounds 3D printing materials was almost negligible, which indicates that the thermal properties of PLA coffee grounds 3D printing materials are comparable to those of PLA, and that the processing temperature and FDM printing temperature of the PLA filament are suitable for application to the PLA coffee grounds 3D printing material system.

1 citations

Journal ArticleDOI
TL;DR: In this article, a novel packaging was synthesised by coating polyvinyl chloride (PVC) film with polyvinylamine/polyvinyl alcohol (PVAm/PVA) mixture which can effectively inhibit the migration of DOP in this paper.
Abstract: The novel packaging was synthesised by coating polyvinyl chloride (PVC) film with Polyvinylamine/Polyvinyl alcohol (PVAm/PVA) mixture which can effectively inhibit the migration of DOP in this paper. The effect of PVAm/PVA mixture on inhibiting DOP migration was detected via extraction tests. The results showed that the novel packaging significantly reduced the migration rate of DOP compared with the control (PVC film). After 24h extracted by hexane 40% PVAm in mixture being coated on PVC had the lowest migration rate (6.20%) among the samples, while 7.60% is the migration rate of control sample. Tensile properties analysis indicated the elongation at break and tensile strength of samples coating PVAm/PVA higher than control sample. The thermogravimetric analysis demonstrated that the PVAm/PVA mixed solution can deduce thermogravimetric rate. Therefore, coating PVC with PVAm/PVA mixture is an effective approach to suppress the migration of DOP.

Cited by
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TL;DR: In this article , the effects of pre-treatment parameters on the micro-morphology, chemical compositions, chemical functional groups, macro-physical/mechanical properties, micro-mechanic properties, and surface stress of untreated and treated arc-shaped bamboo sheets were investigated.

3 citations

Journal ArticleDOI
TL;DR: In this article , Phytic acid-based hybrid complexes were fabricated on the bamboo surfaces for improving its interfacial property and mildew resistance, and the results showed that the modified bamboo samples exhibited better anti-mildew properties than those of the control.

2 citations

Journal ArticleDOI
01 Jun 2023-Polymers
TL;DR: In this article, the authors investigated the addition of spent coffee grounds (SCG) as a valuable resource to produce biocomposites based on polylactic acid (PLA), which has a positive biodegradation effect but generates poor proprieties, depending on its molecular structure.
Abstract: This work investigated the addition of spent coffee grounds (SCG) as a valuable resource to produce biocomposites based on polylactic acid (PLA). PLA has a positive biodegradation effect but generates poor proprieties, depending on its molecular structure. The PLA and SCG (0, 10, 20 and 30 wt.%) were mixed via twin-screw extrusion and molded by compression to determine the effect of composition on several properties, including mechanical (impact strength), physical (density and porosity), thermal (crystallinity and transition temperature) and rheological (melt and solid state). The PLA crystallinity was found to increase after processing and filler addition (34–70% in the 1st heating) due to a heterogeneous nucleation effect, leading to composites with lower glass transition temperature (1–3 °C) and higher stiffness (~15%). Moreover, the composites had lower density (1.29, 1.24 and 1.16 g/cm3) and toughness (30.2, 26.8 and 19.2 J/m) as the filler content increased, which is associated with the presence of rigid particles and residual extractives from SCG. In the melt state, polymeric chain mobility was enhanced, and composites with a higher filler content became less viscous. Overall, the composite with 20 wt.% SCG provided the most balanced properties being similar to or better than neat PLA but at a lower cost. This composite could be applied not only to replace conventional PLA products, such as packaging and 3D printing, but also to other applications requiring lower density and higher stiffness.
Journal ArticleDOI
27 Jun 2023-Small
TL;DR: In this article , the intrinsic performance enhancement of Ni SACs anchored on quasi-one-dimensional graphene nanoribbons (GNRs) synthesized is demonstrated by longitudinal unzipping carbon nanotubes (CNTs).
Abstract: Ni single-atom catalysts (SACs) are appealing for electrochemical reduction CO2 reduction (CO2 RR). However, regulating the balance between the activity and conductivity remains a challenge to Ni SACs due to the limitation of substrates structure. Herein, the intrinsic performance enhancement of Ni SACs anchored on quasi-one-dimensional graphene nanoribbons (GNRs) synthesized is demonstrated by longitudinal unzipping carbon nanotubes (CNTs). The abundant functional groups on GNRs can absorb Ni atoms to form rich Ni-N4 -C sites during the anchoring process, providing a high intrinsic activity. In addition, the GNRs, which maintain a quasi-one-dimensional structure and possess a high conductivity, interconnect with each other and form a conductive porous framework. The catalyst yields a 44 mA cm-2 CO partial current density and 96% faradaic efficiency of CO (FECO ) at -1.1 V vs RHE in an H-cell. By adopting a membrane electrode assembly (MEA) flow cell, a 95% FECO and 2.4 V cell voltage are achieved at 200 mA cm-2 current density. This work provides a rational way to synthesize Ni SACs with a high Ni atom loading, porous morphology, and high conductivity with potential industrial applications.
Journal ArticleDOI
15 Jun 2023-Forests
TL;DR: In this article , an FA and caprolactam combinational modifier was used to treat masson pine (Pinus massoniana Lamb.) earlywood and latewood, and the synergistic interaction of both components with the wood cell walls was systematically evaluated via microstructural, chemical, and thermal analysis using scanning electron microscopy (SEM), infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectrometry (XPS), and differential scanning calorimetry (DSC).
Abstract: Furfurylated wood has many advantages, such as decay resistance, dimensional stability, hardness, etc. However, furfurylation increases the brittleness and decreases the flexural resistance of wood, which greatly limits its application. Therefore, caprolactam (CPL) is incorporated with furfuryl alcohol (FA) to improve the performance of furfurylated wood. In this study, an FA and CPL combinational modifier was used to treat masson pine (Pinus massoniana Lamb.) earlywood and latewood. The synergistic interaction of both components with the wood cell walls was systematically evaluated via microstructural, chemical, and thermal analysis using scanning electron microscopy (SEM), infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectrometry (XPS), and differential scanning calorimetry (DSC). The SEM images showed that polymerized modifiers were distributed in tracheids, ray cells, and pits, with a higher degree of distribution in latewood tissues. The FA-CPL co-treatment led to the highest degree of distribution in cell cavities as well as of cell wall swelling. The results of the weight percentage gain (WPG) of modified wood agreed with the SEM findings that the FA-CPL co-treatment could more effectively increase the WPG than individual modification. The results of FTIR and XPS revealed that FA and CPL might chemically bind with each other as well as react with lignin and hemicellulose in the cell walls during the curing process. In addition, the interactions between modifiers and cell walls were slightly different for earlywood and latewood. DSC analysis indicated that the wood hygroscopicity decreased and the thermal stability improved after modification.