COMBUSTION AND FLAME
·
2024
·
IF 5.8
Jiabao Zhu,Shuo Wang,Weiqiang Xiong,Jun Wang,Xiaodong Li,Meishuai Zou
Aluminum-lithium alloy powder exhibits better thermal properties and combustion performances than aluminum , thus showing promising applications in the field of energetic materials such as explosives and propellants. However, the high activity of lithium also raises issues of stability and compatibility with propellant components, deteriorating the powder's overall performance. In this study, a facile coating method is presented using 1H,1H,2H,2H-perfluorooctyltriethoxysilane (PFOTS) as a surfactant to coat hydroxyl‑terminated polybutadiene (HTPB) on the surface of Al-5Li powder, forming the core-shell composite Al-5Li@HTPB. The microstructure and chemical composition characterized by SEM, EDS , XPS , FT-IR, and nano-CT demonstrated that a uniform and dense layer was successfully coated on the surface. The thermal analysis results showed a significant improvement in the thermal properties and stability compared to pure Al-5Li. In addition, ignition tests were conducted, and the results showed that Al-5Li@HTPB could reduce the ignition delay time and significantly reduce agglomeration. Overall, our strategy provides a novel method to solve the stability issues of Al-Li powders and simultaneously enhance combustion performance.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
Particuology
·
2024
·
IF 4.1
Chen Dong,Yi Wang,Kanghui Jia,Dan Song,Xiaolan Song,Chongwei An
Boron nanoparticles , with their remarkably high gravimetric and volumetric calorific values, emerge as the most promising fuel in energetic fields. However, challenges such as susceptibility to oxidation , high ignition temperature , and low combustion efficiency have constrained their further applications. In this study, we fabricated high explosives based nano-boron microspheres with uniform size using the electrostatic spray method, in which the boron nanoparticles and high explosives (CL-20 or PETN) are closely bonded together by fluorinated polymer (F 2602 ) and evenly distributed. The results indicated that the microspheres exhibited high sphericity and showed an enhanced antioxidant capability. The addition of high-energy explosives not only reduced the thermal oxidation temperature of nano-boron powder within the microspheres but also significantly enhanced the pressurization rate. Additionally, the microspheres with added high-energy explosives released more energy during the combustion process. Compared to physically mixed samples, electrostatically sprayed microspheres with a uniform microstructure still exhibited higher reactivity. Therefore, the design and synthesis of microspheres with controllable structures using the electrostatic spray method show promising application prospects.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Chong Wan,Yushu Xiong,Honghong Qin,Zhao Qin,Suhang Chen,Kangzhen Xu
Nanothermites are presenting competitive advantage potential in military and civilian applications, but high electrostatic discharge (ESD) sensitivity severely hinders their preparation, storage and usage. Aiming to improve the safety and combustion properties of energetic materials (EMs), the two-dimensional semiconductor materials graphite carbon nitride (g-C 3 N 4 also abbreviated as CN) was inserted into the Al/CuO mixture via the one-step sol-freeze-drying method. The successful preparation of samples was confirmed by morphological and chemical bond characterization. Then DFT calculation and BET tests prove that more active sites exist in reaction interface, and the adsorption between Al atoms and CuO unit cells are easier due to polyvinylpyrrolidone (PVP) and g-C 3 N 4 functioning, thereby improving the combustion of Al/CuO and ESD safety. The Al/CuO/CN nanocomposite with 2.5 wt% CN has an ESD ignition threshold of 3.2 mJ and realizes maximal reaction energy and constant volume heat of combustion ( Q v ) of 1400.4 J·g −1 and 5896 J·g −1 , respectively. As the CN content grows to 10.0 wt%, the ESD ignition threshold keeps decreasing to 8.45 mJ. Additionally, PVP and CN show superior advantages in regulating the combustion of Al/CuO, and the possible effect mechanism is investigated. This work will provide a fresh strategy for extending applications of nanothermites.
研究领域:
材料科学
·
能源科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2024
·
IF 6.3
Bohan Liang,Ke Liu,Junming Dai,Wenxing Chen,Wangyang Lu
A polymer-type flame retardant (PFR) based on a 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivative was synthesised here to improve the flame retardancy of polyamide 6 (PA6). The chemical structure and thermal property of the PFR were characterised by Fourier-transform infrared (FTIR) spectroscopy, nuclear magnetic resonance spectroscopy, gel permeation chromatography (GPC), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The PFR and PA6 were melt-blended to obtain a flame-retardant polyamide 6 (FRPA6). Its thermal property, mechanical property and flame retardancy were characterised via TGA, DSC and tensile, impact, vertical burning and limiting oxygen index (LOI) tests. Its flame-retardant mode of action was analysed by scanning electron microscopy, FTIR spectroscopy, cone calorimetry and pyrolysis-gas chromatography-mass spectrometry. The FRPA6 with a phosphorus content of 3000 ppm passed the UL-94 V-0 rating, and the LOI of the FRPA6 with a phosphorous content of 5000 ppm reached 28.8 %. Compared with pure PA6 , the peak heat release rate, total heat release and effective heat of FRPA6–5000 were reduced by 35.4 %, 21.9 % and 26.5 %, respectively. These results indicate that the flame-retardant mode of action of PFR mainly involved the quenching effect of phosphorus-containing radicals in the gas phase.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR MATERIALS AND ENGINEERING
·
2022
·Vol. 307
·期 11
·2200408
·
IF 4.402
Wen-Hua Zhao,Jing-Wen Wang,Guo-Chao Zhuang,Dong-Yue Liu,Chuang-Chuang Sun
A reactive flame retardant (DTP) is successfully synthesized and characterized, and then incorporated into epoxy resin (EP) as a co-curing agent. The thermal stabilities and flame-retardant properties of epoxy thermosets are evaluated. Compared to neat EP, the thermogravimetric analysis (TG) results show that the thermal decomposition rate of EP/DTP is reduced by 45% and the char yield at 750 °C is increased by 67%, when the addition amount of DTP is 12 wt%. In the cone calorimetry test (CCT), the values of the peak of heat release rate (pk-HRR), total heat release (THR), total smoke produce (TSP), and average of effective heat combustion (av-EHC) of EP-DTP-12 are exhibited a reduction of 36.6%, 26.4%, 40.5%, and 23.6% relative to neat EP, respectively. Meanwhile, the value of the limiting oxygen index (LOI) of EP/DTP-12 can reach 34.83%, and 6 wt% or more loading of DTP make EP/DTP pass the V-0 rating in the UL-94 test. Moreover, the flame-retardant mechanism is investigated by thermogravimetric analysis/infrared spectrometry (TG-IR) and scanning electron microscopy (SEM), which can be summarized into two aspects: the quenching effect of phosphorus-containing radicals and diluting effect of nonflammable gases in the gas phase, and the barrier effect of char layer in the condensed phase.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Defence Technology
·
2025
·
IF 5.9
Xiandie Zhang,Zhijie Fan,Heng Xu,Jinbin Zou,Chongqing Deng,Xiang Zhou,Xiaode Guo
Al/NH 4 CoF 3 - Φ ( Φ = 0.5, 1.0, 1.5, 2.0 and 3.0) binary composites and Al-NH 4 CoF 3 @P(VDF-HFP) ternary composites are fabricated via ultrasonication-assisted blending and electrostatic spraying. The effect of equivalence ratio ( Φ ) on the reaction properties is systematically investigated in the binary Al/NH 4 CoF 3 system. For ternary systems, electrostatic spraying allows both components to be efficiently encapsulated by P(VDF-HFP) and to achieve structural stabilization and enhanced reactivity through synergistic interfacial interactions. Morphological analysis using SEM/TEM revealed that P(VDF-HFP) formed a protective layer on Al and NH 4 CoF 3 particles, improving dispersion, hydrophobicity (water contact angle increased by 80.5% compared to physically mixed composites) and corrosion resistance. Thermal decomposition of NH 4 CoF 3 occurred at 265 °C, releasing NH 3 and HF, which triggered exothermic reactions with Al. The ternary composites exhibited a narrowed main reaction temperature range and concentrated heat release, attributed to improved interfacial contact and polymer decomposition. Combustion tests demonstrated that Al-NH 4 CoF 3 @P(VDF-HFP) achieved self-sustaining combustion. In addition, a simple validation was done by replacing the Al component in the aluminium-containing propellant, demonstrating its potential application in the propellant field. This work establishes a novel strategy for designing stable, high-energy composites with potential applications in advanced propulsion systems.
研究领域:
材料科学
·
化学工程
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
JOM
·
2025
·
IF 2.3
Chen Jialin,An Ming,Dai Mengnan,Li Shutao,Chen Yeqing,Song Rui,Song Jiaxing,Chen Longming,Zhong Xiting,Tian Quanwei
The properties of oxidants significantly affect the thermal and combustion properties of nanothermites, and alpha and beta-MnO 2 nanorods with similar morphological appearances were prepared using the hydrothermal method. Corresponding nanothermites were prepared employing the electrostatic spraying method and their thermal and combustion properties have been compared through TG-DSC and combustion tests. The aluminothermic reaction process was simulated by molecular dynamics, and the results showed that the β-MnO 2 /Al nanothermite first underwent β-MnO 2 thermal decomposition followed immediately by an aluminothermic reaction, whereas the α-MnO 2 /Al nanothermite underwent a direct aluminothermic reaction. In contrast, the α-MnO 2 /Al nanothermite could release more heat. According to thermal analysis, the activation energy of α-MnO 2 /Al nanothermite was 100.15 kJ mol − 1 higher than β-MnO 2 /Al nanothermite, indicating better stability. Combustion experiments showed that the combustion propagation rate of the α-MnO 2 /Al nanothermite was faster than the β-MnO 2 /Al nanothermite. The results have been verified and the reaction process has been exhibited using molecular dynamics to simulate the aluminothermic reaction process. The notable differences in the thermal and combustion properties of nanothermites containing MnO 2 with varying phases can be attributed to the distinct crystal structures of α-MnO 2 and β-MnO 2 . The alternating 1 × 1 and 2 × 2 tunnel structure of α-MnO 2 is more stable, whereas β-MnO 2 undergoes thermal decomposition before the aluminothermic reaction.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
FirePhysChem
·
2024
·
IF 0
Jiashuai Wang,Bo Wu,Lingfeng Yang,Yuan Bian,Renjie Li,Ke Zeng,Juan Zhu,Liangyou Zhao,Jinpeng Shen,Chonghua Pei
Thermites are widely used in propellants, explosives and ignition materials because of their high heat release rate and good combustion efficiency. Structural control over thermites to achieve improved performance leads to a promising research area. Among these, core-shell structured composites have attracted wide attention due to their excellent properties and close contact among components. Herein, core-shell structured α -AlH 3 /Fe 2 O 3 thermites were prepared, which exhibit high heat-release and excellent combustion performance. At an equivalence ratio of 2.0, the core-shell structured α -AlH 3 /Fe 2 O 3 has the most heat release (1213.8 J/g) and the lowest reaction activation energy (147.5 kJ/mol). The ignited combustion performance of α -AlH 3 /Fe 2 O 3 was notably strengthened by the shorter ignition delay period (11 ms). Interestingly, the core-shell structured α -AlH 3 /Fe 2 O 3 was less sensitive to electrostatic discharge, which suggests that the core-shell structured α -AlH 3 /Fe 2 O 3 reaches the goal of high energy release and electrostatic safety. The core-shell thermite system with α -AlH 3 as metal fuel could provide an efficient alternative to hunt for thermites with high reactivity.
研究领域:
材料科学
·
化学工程
·
能源技术
✓ 已验证
DOI
Energetic Materials Frontiers
·
2023
·
IF 0
Yu-shu Xiong,Yong-qi Wang,Chong Wan,Wen-zhen Zhang,Zhao Qin,Su-hang Chen,Kang-zhen Xu
To overcome the agglomeration and insufficient combustion of nano-boron (n-B) powders, this study successfully prepared two novel types of boron-based nanocomposites using the acoustic resonance technology, namely high-substitute nitrochitosan/nano-boron (NCh-B) with ratios of 1:3, 1:5, 1:7 and 1:9, and nitrochitosan/nano-boron powder/nano-titanium (NCh-B-Ti) with Ti contents of 5 wt%, 10 wt%, 15 wt% and 20 wt%. The structural morphologies, laser ignition and combustion properties of the composites were systematically investigated. The results suggest that the addition of NCh can significantly improve the dispersion of n-B. NCh-B exhibited a higher combustion performance than n-B, as evidenced by their ignition delay and flame areas. When the laser power density was 81 W, NCh-B 5 -Ti 15% exhibited a combustion time and an ignition delay of 240 ms and 5.5 ms respectively, which were higher and lower than those of NCh-B 5 (199 ms and 17 ms, respectively). Furthermore, NCh-B 5 -Ti 15% displayed a lower ignition delay than both n-B powders (12 ms) and NCh-B (11 ms), as well as brighter flames and a larger combustion area. Therefore, the addition of n-Ti can promote the combustion of n-B powders, with the combustion products of NCh-B-Ti including H 3 BO 3 , B 2 O 3 , TiB 2 , and TiO. This study provides a new method for improving the ignition performance and combustion efficiency of n-B powders.
研究领域:
材料科学
·
燃烧学
✓ 已验证
DOI
BULLETIN OF THE KOREAN CHEMICAL SOCIETY
·
2016
·Vol. 37
·期 11
·1827-1830
·
IF 0.793
Yanjun Yin,Xueming Li
In this study, an energetic material was prepared by depositing nano-Al on CuO arrays via electrophoretic deposition (EPD), which offers a feasible route for nano-Al integration. The morphology and structure of the CuO arrays and Al/CuO composites were characterized by scanning electron microscopy and X-ray diffraction. The CuO arrays were homogenously salix leaf-like structure with a width of ~150 to 200 nm. The energy density of Al/CuO composites was approximate to 1454.5 J/g by integrating the differential scanning calorimetry (DSC) plot and the combustion performance was recorded by a high-speed camera. Moreover, the combustion flames were violent and the whole reaction process only lasted 72.2 ms, indicating that the energy of the Al/CuO nanothermite can be released effectively.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Wanjun Zhao,Hui Ren,Tao Yan,Yapeng Ou,Qingjie Jiao,Haiyang Wang,Dylan J. Kline,Michael R. Zachariah
This work explores the ignition mechanism of silicon (Si) based thermites, and it is supposed that the phase change of silica (SiO 2 ) coating on the Si core producing fractures may play a crucial role in the ignition of Si-based thermites. Several Si-based thermites were evaluated by the combustion test and calorimeter, and potassium perchlorate (KClO 4 ) is turned out to be a promising oxidizer given the high reactivity and considerable heat release. Titanium (Ti) nanoparticles with a lower onset oxidization temperature than Si were incorporated into Si/KClO 4 system via a facile sonicating method. The ignition temperature of Si/KClO 4 has reduced markedly by ~80–130 °C with significant increases of ~5-8x in pressurization rate and decreases by a factor of ~2–3 in burn time when adding 30–70% Ti by mole into the fuel. The combustion efficiency is improved dramatically from ~59% to ~73%. The enhanced combustion performance could be attributed to the lower ignition temperature of Ti/KClO 4 leading to the initiation reaction of the ternary composites, thus promoting energy release and the reactivity of the ternary system. This work not only investigates the ignition mechanism of Si-based thermites but also sets a stage for tuning the ignition and combustion of Si-based thermites via facile incorporation of Ti nanoparticles.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMERS AND THE ENVIRONMENT
·
2022
·Vol. 30
·期 6
·2516-2533
·
IF 4.705
Han Dequan,Wang Hui,Lu Tingting,Cao Luya,Dai Yufei,Cao Hongzhang,Yu Xiaoli
Abstract As a plastic that can be prepared from biomass resources, polylactic acid (PLA) has the characteristics of being degradable and renewable, and has shown great potential in replacing petroleum-based polymer materials. However, PLA material is flammable, the droplet phenomenon during combustion is still a disadvantage of PLA applications. In this research, a core–shell structure flame retardant was prepared based on polyacrylamide (PAM)/sodium alginate (SA) coated ammonium polyphosphate (APP) via layer-by-layer assembly using water as the assembly medium. The prepared core–shell flame retardant APP@PAM@SA-nDL (where “DL” is the PAM&SA double layer, and “n” represents 1-3DL) was molten compounded with PLA to improve its flame retardancy. APP@PAM@SA-nDL is added to PLA, which not only improves the flame retardancy of PLA composites, but also significantly improves the toughness, and the flame retardancy, flame retardant mechanism, mechanical performance and toughening mechanism of PLA composites were systematically studied. Among the core–shell flame retardants with different layers, the addition of APP@PAM@SA-3DL gives PLA composites excellent flame retardancy and tensile properties. Due to the formation of the cross-linked polymer network structure, 5% APP@PAM@SA-3DL can increase the elongation at break of PLA composites from 19.82 to 294.5%. In addition, 10% of APP@PAM@SA-3DL made the UL-94 of PLA composite materials reach V-0 level and increased the LOI from 19.7% (neat PLA) to 29.2%. The analysis of the carbon layer shows that the excellent flame-retardant performance of PLA composites can be attributed to the formation of a dense carbon layer during condensation and the dilution effect of P-containing free radicals, forming a flame-retardant mechanism with a condensed phase as the main component and a gas phase as a supplement. This high toughness flame-retardant PLA composite material has broad application prospects in the textile field. Graphical Abstract
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）