期刊：
Journal of Applied Polymer Science,2024年141(11):e55083- ISSN：0021-8995
通讯作者：
Zhang, XL
作者机构：
[Zhang, Xinli; Shen, Dazhi; Ma, Yulian; Li, Xia] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha, Peoples R China.;[Zhang, XL; Zhang, Xinli] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.
通讯机构：
[Zhang, XL ] C;Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.
关键词：
disposable medical masks;geopolymer;high temperatures;mechanical strengths;polypropylene fiber
摘要：
A tremendous amount of the nonbiodegradable microplastic waste has been generated after the outbreak of COVID-19 by the widespread use of single-use personal protective equipment, especially disposable medical masks (DMMs). This has caused harm to the health and safety of human beings and various organisms. Finding a way to properly deal with these single-use medical wastes has become an urgent problem. In this paper, an innovative way was explored to use DMMs in geopolymer (GP). The physical properties, mechanical strength, and resistance to high temperatures (200-800 degrees C) of the composites were investigated. The findings of the study revealed that DMMs had negligible influence on resistance to high temperatures, but showed a positive influence on enhancing the compressive and flexural strengths of GPs at ambient temperature. The optimum DMMs content was 0.4 wt%, at which the compressive and flexural strengths of the GP composites were enhanced by 5.8% and 22.68% compared with the pure GP, respectively. The same polypropylene (PP) fiber amount increased compressive and flexural strengths by 7.49% and 9.76%, respectively. This thus confirmed that DMMs can be sustainably utilized in green building materials, playing a role as PP fibers toughening and contributing to the effective management of waste plastics. Disposable medical masks was attempted to use in fly ash-based geopolymer, which improved the properties of geopolymers at ambient temperature and did not obviously deteriorate the properties at high temperatures.image
摘要：
Combining bamboo processing residues with lightweight magnesium oxychlorides can produce new composite building materials that increase the utilization rate of bamboo and also improve the performance of lightweight magnesium oxychlorides. However, the incompatible interface between the two materials leads to the poor performance of the resulting composites, which limits their application in construction engineering. In this paper, a synergistic effect between surfactants and styrene-butadiene latex was used to enhance the interfacial compatibility between bamboo scraps and lightweight magnesium oxychlorides. The structure formed between the two acted as a "bridge" that enhanced the cross-linking between bamboo scraps and lightweight magnesium oxychloride, thus forming a more stable bamboo fiber-lightweight magnesium oxychloride network. The lightweight composite material obtained in this paper showed a maximum compressive stress of 6.5 MPa and a softening coefficient of 0.75.It shows great development potential in the application of light weight, high strength and water resistance building decoration materials.
通讯机构：
[Wu, YQ; Tian, CH; Qing, Y ] C;Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.
关键词：
carbon nanotube encapsulating;efficiency and durability;Fe doping;hierarchical wood substrate;high current density
摘要：
Precise morphology design and electronic structure regulation are critically significant to promote catalytic activity and stability for electrochemical hydrogen production at high current density. Herein, the carbon nanotube (CNT) encapsulated Fe-doped NiCoP nanoparticles is in-situ grown in hierarchical carbonized wood (NCF0.5P@CNT/CW) for water splitting. Coupling merits of porous carbonized wood (CW) substrate, CNT encapsulating and Fe doping, the NCF0.5P@CNT/CW features remarkable and durable electrocatalytic activity. The overpotentials of NCF0.5P@CNT/CW at 50 mA cm-2 mV and 205 mV for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) and features high current density of 800 mA cm-2 within 300 mV for both OER and HER. Moreover, NCF0.5P@CNT/CW displays outstanding overall water splitting performance (eta 50 = 1.62 V and eta 100 = 1.67 V), outperforming Pt/CRuO2 (eta 50 = 1.74 V), and can achieve the current density of 700 mA cm-2 at a lower cell voltage of 1.78 V. Overpotential is only 4.0 % decay after 120 h measurement at 50 mA cm-2. Density functional theory (DFT) calculations reveals Fe doping optimizes the binding energy and Gibbs free energy of intermediates, and regulates d-band center of NCF0.5P@CNT/CW. Such synergistic strategy of morphology manipulation and electronic structure optimization provides a spark for developing effective and robust bifunctional catalysts. The synergistic strategy of morphology manipulation and electronic structure optimization by encapsulating Fe-doped NiCoP into carbon nanotube (CNT) and in situ growing in hierarchical carbonized wood (CW) is employed to fabricate NCF0.5P@CNT/CW catalyst. The NCF0.5P@CNT/CW presents remarkable and durable performance for oxygen evolution reaction (OER), hydrogen evolution reaction (HER) and overall water splitting, which provides an avenue for the electrochemical hydrogen production at high current density.image
通讯机构：
[Wu, YQ; Tian, CH ] C;Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.
关键词：
typical softwood;typical hardwood;wood aerogel;nanofibril network;formation process
摘要：
The construction of networks within natural wood (NW) lumens to produce porous wood aerogels (WAs) with fascinating characteristics of being lightweight, flexible, and porous is significant for the high value-added utilization of wood. Nonetheless, how wood species affect the structure and properties of WAs has not been comprehensively investigated. Herein, typical softwood of fir and hardwoods of poplar and balsa are employed to fabricate WAs with abundant nanofibrillar networks using the method of lignin removal and nanofibril's in situ regeneration. Benefiting from the avoidance of xylem ray restriction and the exposure of the cellulose framework, hardwood has a stronger tendency to form nanofibrillar networks compared to softwood. Specifically, a larger and more evenly distributed network structure is displayed in the lumens of balsa WAs (WA-3) with a low density (59 kg m-3), a high porosity (96%), and high compressive properties (strain = 40%; maximum stress = 0.42 MPa; height retention = 100%) because of the unique structure and properties of WA-3. Comparatively, the specific surface area (SSA) exhibits 25-, 27-, and 34-fold increments in the cases of fir WAs (WA-1), poplar WAs (WA-2), and WA-3. The formation of nanofibrillar networks depends on the low-density and thin cell walls of hardwood. This work offers a foundation for investigating the formation mechanisms of nanonetworks and for expanding the potential applications of WAs.
期刊：
Industrial Crops and Products,2024年209:117944 ISSN：0926-6690
通讯作者：
Li, GY
作者机构：
[Chen, Yuan; Guo, Dengkang; Zhang, Yiyuan; Li, Gaiyun; Li, GY] Chinese Acad Forestry, Res Inst Wood Ind, 1 Dongxiaofu Xiangshan Rd, Beijing 100091, Peoples R China.;[Cao, Yuan] Chinese Acad Forestry, State Key Lab Tree Genet & Breeding, Beijing 100091, Peoples R China.;[Wu, Yiqiang; Qing, Yan] Cent South Univ Forestry & Technol, Sch Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Li, GY ] C;Chinese Acad Forestry, Res Inst Wood Ind, 1 Dongxiaofu Xiangshan Rd, Beijing 100091, Peoples R China.
关键词：
Bio-composites;Self-bonding;Particle size high strength;Eco-friendly
摘要：
Green and low-carbon bio-composites from wood fibers are in great demand in the further due to the global sustainable development. In this work, we successfully manufactured the fully bio-composites with excellent mechanical properties and improved water resistance using the dialdehyde wood fibers as the “glue” and untreated poplar wood fibers with lower particle size. The high reactive aldehyde groups provided internal chemical connection between fiber compositions and uniform size offered tightly connected structure and physical winding, which were synergistically contributed to superior performances of self-bonding bio-composites. The self-adhesive bio-composites owned outstanding flexural strength (105.2 MPa), tensile strength (35.6 MPa), internal bond strength (5.1 MPa), and hardness (0.3 GPa), better than most of the reported non-adhesive biomass materials. An innovative hydrobromic acid destruction method was used to prove the self-assembly mechanism and contributions. Both of the direct characterization and reverse destruction illustrated the covalent and hydrogen bond synergistic self-adhesive contribution of dialdehyde oxidation and homogenization. The self-bonding bio-composites have the potential to be applied to high strength outdoor household materials and structural buildings, which corresponds with the notions of carbon storage, eco-friendly, and degradation.
期刊：
Green Chemistry,2024年26(6):3356-3367 ISSN：1463-9262
通讯作者：
Wu, YQ;Jiang, Jianchun;Wang, K
作者机构：
[Li, Zhaoshuang; Liu, Chao; Wu, Zhiping; Qing, Yan; Wu, Yiqiang] Cent South Univ Forestry & Technol, Sch Mat Sci & Engn, Changsha 410004, Peoples R China.;[Jiang, Jianchun; Liu, Chao; Cai, Tingting; Wang, Kui; Wang, K; Jiang, JC] Inst Chem Ind Forest Prod, Chinese Acad Forestry, Key Lab Biomass Energy & Mat Jiangsu Prov, Natl Engn Lab Biomass Chem Utilizat, Nanjing 210042, Jiangsu, Peoples R China.;[Chen, Yuwei] Yancheng Inst Technol, Sch Automot Engn, Yancheng 224051, Peoples R China.;[Zhang, Xiaolei; Jia, Shuya] Univ Strathclyde, Dept Chem & Proc Engn, Glasgow City G1 1XJ, Scotland.
通讯机构：
[Wu, YQ ] C;[Wang, K ; Jiang, JC] I;Cent South Univ Forestry & Technol, Sch Mat Sci & Engn, Changsha 410004, Peoples R China.;Inst Chem Ind Forest Prod, Chinese Acad Forestry, Key Lab Biomass Energy & Mat Jiangsu Prov, Natl Engn Lab Biomass Chem Utilizat, Nanjing 210042, Jiangsu, Peoples R China.
摘要：
Solvents play a critical role in the lignin hydrogenation process. However, elucidating the role of solvents in lignin hydrogenation solely through experimental methods presents considerable challenges. The present report integrates experimental results, quantum chemical calculations, and molecular dynamics simulations to study the effect of solvents on the hydrogenation of lignin on Ru/C to produce phenolic compounds. Solvents not only disperse the substrate and promote the mass transfer process in the hydrogenation reaction, but also significantly affect the hydrogenation reaction rate of lignin. We show that the hydrogenation reaction rates of lignin in different solvents differ by an order of magnitude (isopropanol > methanol > water > γ-valerolactone > tetrahydrofuran). By innovatively combining quantum chemical calculations with experimental results, it was reported for the first time that solvent affects the free energy barrier by regulating the properties of the transition state (C–O bond strength), thereby affecting the lignin hydrogenolysis reaction rate. Based on molecular dynamics simulations, this study investigated the interaction between lignin and various solvent molecules. The research results confirmed that solvent molecules regulate the solvent shell on the surface of lignin, thereby influencing the mechanism of the hydrogenation reaction process.
作者机构：
[Yanglin Ge; Xingong Li; Xiaofeng Hao] College of Material Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China;Authors to whom correspondence should be addressed.;[Tonghua Lu] Treezo Research Department, Treezo New Material Technology Group Co., Ltd., Hangzhou 311100, China;[Shoulu Yang] Forestry Industry Research Department, Guizhou Academy of Forestry, Guiyang 550005, China;[Tong Lu] College of Material Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Treezo Research Department, Treezo New Material Technology Group Co., Ltd., Hangzhou 311100, China
通讯机构：
[Kang Xu; Xianjun Li] C;College of Material Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Authors to whom correspondence should be addressed.
关键词：
bamboo scrimber;hot-pressing parameters;temperature distribution;vapor-pressure distribution
摘要：
This study investigated the heat-transfer behavior of heat-treated and phenolic resin-impregnated bamboo bundle slabs during the hot-pressing process. The significance of these findings lies in their potential to drive advancements in hot-pressing technology, contribute to energy-conservation efforts, and facilitate emission reduction within the bamboo scrimber industry. In this study, the variations in temperature and vapor pressure were investigated during the hot-pressing of bamboo slabs under various conditions, including hot-pressing temperatures (140 °C, 150 °C, 160 °C, and 170 °C), hot-pressing holding times (15 min, 20 min, 25 min, and 30 min), and hot-pressing pressures (4 MPa, 5 MPa, 6 MPa, and 7 MPa). This was achieved using thermocouple sensors and a self-made vapor pressure-monitoring system. The results indicated that higher hot-pressing temperatures significantly increased the heating rate, peak temperature, and core-layer vapor peak pressure of the bamboo bundle slab, with the vapor peak pressure at 170 °C being twice that at 140 °C. Furthermore, extending the holding time had a lesser effect on increasing the peak temperature of the slab but significantly increased the peak vapor pressure in the core layer. Thus, increasing the hot-pressing pressure proved beneficial for slab heating but had a lesser effect on the surface and core-layer peak temperatures. The core-layer vapor pressure of the slab subjected to a hot-press pressure of 7 MPa was 1.8 times higher than that at 4 MPa.
摘要：
Highly efficient resource recycling and comprehensive utilization play a crucial role in achieving the goal of reducing resource wasting, environmental protection, and achieving goal of sustainable development. In this work, the two kinds waste resources of agricultural rice husk and metal ions (Co, Ni, and Mn) from spent lithium-ion batteries have been skillfully utilized to synthesize novel Fenton-like catalysts. Desiliconized rice husk carbon (DRHC) with rich pore structure and large specific surface area from rice husk has been prepared and used as scalable carrier, and dandelion-like nanoparticles cluster could be grown in situ on the surface of the carrier by using metal ions contained waste water. The designed catalysts (X@DRHC) as well as their preparation process were characterized in detail by SEM, TEM, BET, XRD and XPS, respectively. Meanwhile, their catalytic abilities were also studied by activating potassium peroxomonosulfate (PMS) to remove methylene blue (MB). The results indicate X@DRHC displays excellent degradation efficiency on MB with wide pH range and stable reusability, which is suitable for the degradation of various dyes. This work has realized the recycling and high-value utilization of waste resources from biomass and spent lithium-ion batteries, which not only creates an efficient way to dispose waste resources, but also shows high economic benefits in large-scale water treatment.
通讯机构：
[Pang, XC; Zhu, Y ] C;Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.
关键词：
Cellulose nanocrystals;Compatibility and dispersion;Poly(lactic acid)
摘要：
Poly(lactic acid) (PLA) composites reinforced with cellulose nanocrystals (CNCs) are promising biodegradable materials. However, the poor compatibility and dispersion of CNCs in the PLA matrix remain a significant obstacle to improving the properties of composites. In this study, the modified CNC (CNC-D) was prepared through sulfonation treatment, followed by modification with didecyl dimethyl ammonium chloride (DDAC). Then, CNC-D was mixed with PLA to prepare composite films (PLA-CNC-D). The results revealed that the PLA-CNC-D had higher tensile strength and elongation at break than PLA-CNC at 3wt% nanofiller content, increasing by 41.53 and 22.18%, respectively. SEM and DSC analysis indicated that surface modification improved the compatibility and dispersion of CNC-D in the PLA matrix. The sulfonation process increased the anion content on the surface of CNC-D, enabling the CNC-D surface to adsorb more cationic DDAC, consequently sharply reducing the hydrophilicity of CNC-D. Moreover, the PLA-CNC-D exhibited excellent antibacterial activity against S. aureus and E. coli. In summary, this study provides a novel CNC modification approach to enhance the physical properties and antibacterial activity of PLA composite films, enlarging the application of degradable PLA composites.
作者机构：
State Key Laboratory of Precision Manufacturing for Extreme Service Performance, Changsha, China;School of Mechanical and Electrical Engineering, Central South University, Changsha, China;[Kejun Li] School of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, China;[Hongqiang Chen; Ruiheng Xia; Yi Zhang; Hua Deng] State Key Laboratory of Precision Manufacturing for Extreme Service Performance, Changsha, China<&wdkj&>School of Mechanical and Electrical Engineering, Central South University, Changsha, China
摘要：
The 3-D scanning system used in some engineering requires regular calibration; achieving a concise and efficient calibration process is crucial. A conventional method requires accurate marker coordinates relative to the scanning systems. Nevertheless, this procedure involves additional bulky measurement equipment. Although attempts have been made to calibrate the scanning system based on the shape of a calibration object, these approaches are limited to calibrating parameters that influence the shape of the scanned object. This study introduces an internal parameter self-calibration method for a 3-D laser scanning system employing a 2-D light detection and ranging (LiDAR) and rotating platform. The calibration process involves using a cube with known side lengths as the calibration object. After calibrating specific geometric parameters, a calibration method based on single-coordinate information is proposed to correct other parameters that do not impact the scanned object’s shape. This calibration method is straightforward and suitable for rapid ON-site engineering calibration. Experiments and simulations demonstrate the effective calibration of system parameters, and the accuracy of the scanning system was improved after calibration.
通讯机构：
[Yue, K ] N;Nanjing Tech Univ, Coll Civil Engn, Nanjing 211800, Peoples R China.
关键词：
Chinese fir;Thermal treatment;Inorganic impregnation;Compression;Mechanical properties;Fire resistance
摘要：
Fast-growing wood species are unsuitable for direct use in load-bearing structures due to their loose fiber structure, low mechanical strength, and inadequate combustion performance. Traditional impregnation using low-molecular-weight resin may enhance certain characteristics but also poses environmental pollution risks. This study explores an alternative approach: subjecting Chinese fir lumbers to thermal treatment, impregnation with an inorganic solution, compression, and utilization as exposed side laminas for glulam beams. The fire performance of full-scale beams was evaluated under three-side fire exposure conditions. Results revealed that addressing the mechanical deficiencies of thermally treated wood could be achieved through 2.0 mol/L inorganic solution impregnation combined with a 20% compression ratio. The modifier weight percent gains in specimens after thermal treatment increased by 24.8% under identical conditions. Composite modification notably enhanced both mechanical and combustion properties, manifesting promising flame-retardant effects. Building upon these findings, fire-resistant laminas were created and applied to the tensile zone of the glulam beam to investigate residual bearing capacity post three-side fire exposure. After 60 min, the modified laminas-containing beam in the fire-exposed tension zone showed a 31.4% increase in residual bearing capacity over the untreated beam. This study underscores that the combined modification methods are not only cost-effective and environmentally friendly but also establish a vital theoretical foundation for safeguarding the structural safety of rapidly cultivated fast-growing wood in fire scenarios.
摘要：
The construction of advanced transition metal oxide (TMO)/carbon anodes to substitute graphite is always being an enormous challenge for the evolution of lithium–ion batteries (LIBs). Herein, a g–C3N4–assisted pyrolysis strategy is exploited to produce Mn2O3 nanoparticles embedded into N–doped carbon (Mn2O3@NC) hybrids. The results confirm that g–C3N4 plays three critical roles (dispersing agent, pore–forming agent and doping agent) in producing Mn2O3@NC hybrids. In the meantime, it is verified that the feed of Mn source greatly affects the synthesis of Mn2O3@NC hybrids. As a consequence, the resultant Mn2O3@NC–M (M means medium loading of Mn source) reaches a balanced proportion of Mn2O3 and NC, and contemporaneously displays a series of intriguing features, including ultrafine Mn2O3 nanoparticles, large specific surface area, rich mesopores and much high N doping amount. Benefitting from these advantages, the obtained Mn2O3@NC–M shows much enhanced cycling stability and rate performance when engaged as an battery anode.
期刊：
Journal of Molecular Liquids,2024年395:123964 ISSN：0167-7322
通讯作者：
Du, K;Dou, JK
作者机构：
[Dou, Jinkang; Xu, Longfei; Du, Kun; Bai, Yuanjuan; Zhao, Zhao; Tang, Jun; Luo, Yongfeng; Lu, Zhichao; Wang, Ziyi; Zhang, Shuaijie] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Hunan Prov Key Lab Mat Surface & Interface Sci & T, Shaoshan South Rd 498, Changsha 410004, Peoples R China.;[Dou, JK; Dou, Jinkang] Xian Modern Chem Res Inst, Dept Energet Mat Sci & Technol, Xian 710065, Peoples R China.
通讯机构：
[Du, K ] C;[Dou, JK ] X;Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Hunan Prov Key Lab Mat Surface & Interface Sci & T, Shaoshan South Rd 498, Changsha 410004, Peoples R China.;Xian Modern Chem Res Inst, Dept Energet Mat Sci & Technol, Xian 710065, Peoples R China.
摘要：
In this work, a cost-effective and eco-friendly coordination polymer (Zr-CP) was synthesized through the combination of natural amino acids as ligands with Zr4+ metal cation under aqueous conditions at room temperature and used for the treatment of dyeing wastewater. The results showed that Zr-CP exhibited a high adsorption potential for Congo red (CR) in various simulated dyeing effluents. It possesses a theoretical adsorption capacity for CR up to 381.68 mg/g at room temperature 25 celcius in pH 7, probably due to the abundance of primary amino functional groups in its chemical structure. The thermodynamic analysis indicates that the use of Zr-CP as an adsorbent in the wastewater purification process endothermic and spontaneous in nature. Among the tested isotherms, the Langmuir model was found to best fit the equilibrium data, with a coefficient R2 value of 0.98. Besides, the adsorption behavior of this bio-based coordination polymer for Congo red was found to adhere to the pseudo-first-order kinetic equation with higher correlation coefficient R2 of 0.98. Moreover, Zr-CP showed outstanding cycle performance and sustained a high dye removal efficiency even after five reuses. These results indicate that Zr-CP, a biologically derived coordination polymer, offers the advantages of affordability and efficiency, making it a promising adsorbent for the removal of organic pollutants from printing and dyeing effluents
通讯机构：
[Tong, ZH ] G;[Zhang, L] U;[Zhang, L ] C;Cent South Univ Forestry & Technol, Minist Forestry Bioethanol Res Ctr, Changsha 410004, Peoples R China.;Georgia Inst Technol, Renewable Bioprod Inst, Sch Chem & Biomol Engn, Atlanta, GA 30332 USA.
关键词：
Lignin depolymerization;Heterogeneous photo -Fenton catalyst;Enol ether intermediates;Recyclability;Selective bond cleavage
摘要：
Photocatalysis, which leverages sustainable solar energy to facilitate the conversion of lignin under mild conditions, has gained considerable research interest. Therefore, our study introduces a novel heterogeneous photoFenton reagent, Fe3O4@GO@TiO2, designed to selectively depolymerize lignin into aromatic chemicals using ultraviolet light as the energy source. This ternary photo-Fenton catalyst could effectively depolymerize approximately 90% of lignin model compounds. The model compounds without or with phenolic OH blocking yield guaiacol exclusively and predominantly guaiacol with aromatic aldehydes, respectively. The lignin degradation mechanism using the photo-Fenton catalyst (Fe3O4@GO@TiO2) involves the formation of an enol ether intermediate, followed by the cleavage of lignin beta-O-4 bonds, facilitated by a mild photon-stimulated reduction-oxidation Fenton process. Notably, the reduced GO plays a crucial role in two aspects. Firstly, it transfers and stabilizes the photoexcited electron-hole pairs. Secondly, it promotes the generation of radicals (center dot OH, center dot OOH) essential for selective degradation of the lignin side chains. Consequently, the average molecular weight of the lignin depolymerized product is half of that of the original lignin. Furthermore, this photocatalyst demonstrates recyclability, retaining 85% of its initial activity after five-time recycling. This tertiary Fentonphotocatalyst provides a novel approach for the selective depolymerization of lignin interunit bonds into valuable phenolic monomers under ambient conditions.
摘要：
Carveol is a rare fine chemical with specific biological activities and functions in nature. The artificial synthesis of carveol from plentiful and cheap turpentine is expected to further improve development of pharmaceutical and industrial applications. A new green catalytic system for the preparation of high-value carveol from alpha-epoxypinane is presented. A novel ammonium salt solid acid (AC-COIMI-NH4PW) was obtained from phosphotungstic acid bonded with imidazole basic site on nitrogen-doped activated carbon which, after ammonia fumigation, presented an excellent catalytic performance for the selective rearrangement of alpha-epoxypinane to carveol in DMF as solvent under mild reaction conditions. At 90 degrees C for 2 h, the conversion of alpha-epoxypinane could reach 98.9% and the selectivity of carveol was 50.6%. The acidic catalytic sites exhibited superior durability and the catalytic performance can be restored by supplementing the lost catalyst. Based on the investigation of catalytic processes, a parallel catalytic mechanism for the main product was proposed from the rearrangement of alpha-epoxypinane on AC-COIMI-NH4PW.
通讯机构：
[Hu, YC ] C;Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.
摘要：
A novel reactive flame retardant based on L-cysteines containing P, N and S flame retardant elements was synthesized, and using its good water solubility, different concentrations of flame retardant poplar wood powder were prepared, and using the hot pressing process method, flame retardant density boards were made and their flame retardancy was studied. The thermogravimetric infrared coupler (TG-FTIR) test and thermal cracking gas mass spectrometer (Py-GC-MS) test both revealed that the flame retardant modified the thermal decomposition pathway of the wood, forming many residues and producing only a small amount of combustible gas. The ultimate oxygen index (LOI) of poplar density board treated with 20% cysteine-based flame retardant was as high as 60.9%. Scanning electron microscopy (SEM) images revealed that the surface of the treated wood powder was rough and that the wood powder particles were interconnected by the flame retardant. This suggests that the flame-retardant molecules have a bridging effect on the inner structure of the density board. Moreover, the cone calorimetry (CONE) experiments showed that with the flame-retardant treatment, there was significant reduction of total heat release (THR) and heat release rate (HRR) of the density board. The outcomes demonstrated the excellent flame retardancy and catalytic carbon formation of the poplar density board treated with the flame retardant. These findings demonstrate the effectiveness of the cysteine-based flame retardant.
摘要：
The key to enhancing the activation efficiency of peroxydisulfate (PDS) lies in facilitating the adsorption of PDS and accelerating the rate of electron transfer at the interface. In this work, the oxygen vacancy (Ovs) concentration of ultrathin Bi4Ti3O12 (BTO) was controlled in situ by high-energy electron beam bombardment. BTOV- 300 exhibited a significant activation effect on PDS. The degradation rate constant (kobs) for the removal of ciprofloxacin (CIP) was measured to be 0.2080 min 1 under visible light irradiation, which was 3.71 times greater than that of the original BTO. Density functional theory calculations uncovered the principal role of oxygen vacancies as active sites for PDS activation. Introducing OVs significantly boosted the adsorption energy of PDS on BTO and lengthened the O-O bond of PDS. This study represents the potential mechanism behind the activation of PDS by BTOV and provides valuable insights for enhancing the photoactivation efficiency of PDS.
