ACTA ASTRONAUTICA
·
2024
·
IF 3.1
Huanhuan Gao,Hui Liu,Peihui Xu,Jianzhong Liu
The potential of the Al-F reaction in suppressing agglomeration during propellant combustion and enhancing combustion performance is investigated by introducing fluorinated graphene as a fluorinated oxidizer. Comparative analyses of ignition combustion and agglomeration behaviors are conducted on novel composite powders and propellant samples modified with varying contents of fluorinated graphene using laser and hot wire ignition visualization systems. Characterizing parameters such as characteristic spectra, flame grayscale, ignition delay time, combustion duration, and burning rate are measured during combustion at different pressures. Additionally, agglomerated particles are collected via quenching techniques under 7 MPa pressure to explore the influence mechanism of fluorinated graphene on agglomeration near the burning surface, and a comprehensive influence mechanism is proposed. Results indicate that fluorinated graphene promotes ammonium perchlorate decomposition, accelerates oxidizing gas release, and enhances thermal conduction at the burning surface. The reaction between Al and F decreases the formation of intermediates (AlO and Al 2 O), while the interaction of F with Al and Al 2 O 3 effectively inhibits the clustering of Al particles, replacing conventional oxidation reactions and resulting in a unique micro-explosion jetting phenomenon. The introduction of 15 % fluorinated graphene concentrates most product particles around 10 μm, enhancing energy release during combustion. Overall, this composite powder containing fluorinated graphene effectively improves the combustion performance of aluminum-containing composite propellants, inhibiting Al particle agglomeration and potentially reducing specific impulse loss in solid rocket motors.
研究领域:
材料科学
·
燃烧学
·
推进剂工程
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS & DESIGN
·
2019
·
IF 5.77
Haoxue Dong,Min Xia,Cuixiao Wang,Guoping Li,Yunjun Luo
Al/NiO nanocomposites are prepared via co -assembly with poly(4-vinylpyridine) (P4VP), and their enhanced energetic properties and combustion performance are studied. The results show that compared with physical mixing method, the structure of the Al/NiO nanocomposites with P4VP is more regular and compact, in which the grain sizes of Al and NiO nanoparticles are reduced from 56 nm and 29 nm to 51 nm and 25 nm, respectively. Therefore, their heat release, the maximum pressure of combustion, pressure rise rate of combustion and the maximum burning rate are greatly enhanced to 2190 J/g, 0.35 MPa, 260 MPa/s and 462 m/s, respectively, better than those obtained by physical mixing method. We further revealed that the reason for these improvements is that our method effectively suppresses the aggregation of nanoparticles, leading to uniform contact and sufficient interfacial area between the oxidant (NiO) and nano-fuel (Al), and thus significantly improving the reaction efficiency.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 8
·3344
·
IF 4.6
Han Rao,Weiping Li,Fuzhen Zhao,Yongfa Song,Huicong Liu,Liqun Zhu,Haining Chen
In order to increase the hardness, wear resistance and corrosion resistance of nickel-based coatings, pure nickel is often co-electrodeposited with silicon carbide (SiC) particles. However, SiC particles tend to agglomerate and precipitate in the bath, which reduces the amounts of nanoparticles and causes nonuniformity. Herein, we solve these problems by using binary non-ionic surfactants (Span 80 and Tween 60) to effectively disperse SiC particles (binary-SiC) in the bath, which suppresses nanoparticles agglomeration and leads to uniformly distributed SiC particles in the composite coatings. In comparison to the Ni/SiC coatings electrodeposited from the commonly used SDS-modified SiC, the coatings prepared with binary-SiC (Ni/binary-SiC) show finer crystallization and a smoother surface. In addition, the Ni/binary-SiC coatings exhibit higher hardness (556 Hv) and wear resistance (2.95 mg cm−2). Furthermore, higher corrosion resistance is also achieved by the Ni/binary-SiC coatings.Keywords:Ni/SiC composite coatings;co-electrodeposition;binary non-ionic surfactants;nanoparticle agglomeration;wear resistance
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2023
·Vol. 48
·期 6
·e202300022
·
IF 1.8
Ximing Zhang,Peng Jin,Wenhao Liu,Tianqi Li,Shuang Liu,Wu Yang,Cong Zhu,Mengze Zheng,Yunjun Luo
In this work, the energetic thermoplastic polymers were synthesized with different ratios of energetic prepolymer glycidyl azide (GAP) and isophorone diisocyanate (IPDI), and used as the binder to prepare fuel-rich propellants based on Al−Mg. The results showed that energetic thermoplastic polymer enabled the fuel-rich propellant a faster flame spread, greater flame strength, and a stronger injection effect of metal droplets. The weight loss (Δ m ) of the propellants increased with GAP content, while the weight loss rate ( D max ) increased similarly. The Δ m increased from 7.92 % to 9.86 % and D max from −0.23 % ⋅ °C −1 to −0.35 % ⋅ °C −1 in the range 100–256.5 °C. The propellant with the highest GAP content (85GAP-Prop) had the lowest apparent activation energy (150.77 kJ ⋅ mol −1 ). The average pressure rate of 85GAP-Prop burning in a closed bomb reached 7.67 MPa ⋅ s −1 and the maximum instantaneous pressure rate could reach 16.52 MPa ⋅ s −1 , significantly higher than the other propellants. The combustion products analysis indicated that the higher GAP content in the GAP-IPDI energetic thermoplastic polymer more significantly reduced the agglomeration of Al particles and improved the loosening of the combustion products. The rapid combustion gas generation characteristic and energy release of energetic thermoplastic polymer enhanced the combustion characteristics of the fuel-rich propellant based on Al−Mg, which promoted dispersion level between the metal droplets. This work provides insight into the combustion principles and performance improvements of fuel-rich propellant based on Al−Mg.
研究领域:
材料科学
·
燃烧与推进
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2024
·
IF 5.6
Bowen Luo,Zhipeng Tian,Chao Wang,Ying Chen,Jianping Liu,Riyang Shu
The development and utilization of renewable lignin from industrial crops to produce high-value bio-based chemicals and fuels is of great significance in reducing dependence on fossil resources and promoting green chemistry. However, conventional metal-supported catalysts often suffer from poor metal dispersion and particle agglomeration during lignin conversion, resulting in insufficient catalytic activity. To address these challenges, a novel biochar-encapsulated cobalt catalyst (Co@BC) was developed in this study for efficient lignin hydrogenolysis. The catalyst formed a unique thin carbon layer structure by encapsulating cobalt nanoparticles in biochar, which enhanced metal dispersion and prevented particle agglomeration. The performance of the catalysts was systematically evaluated at different calcination temperatures. Co@BC-650 showed the best results with a lignin liquefaction degree of 79.7 % and a monophenol yield of 19.1 wt%. This yield was significantly higher than that of the supported Co/BC-650 catalyst, which only reached 15.4 wt%. The thin carbon layer not only facilitated the reduction of cobalt species at 650 °C, but also provided antioxidant protection and maintained the stability of metallic cobalt, which was essential for H 2 adsorption and activation. In addition, Co@BC-650 exhibited excellent stability with little loss of activity after 3 cycles. This study provides an efficient and sustainable method for the selective production of monophenols from renewable lignin from industrial crops, which has the potential to be widely applied for biomass conversion and large-scale sustainable chemical production.
研究领域:
催化
·
可再生能源
·
绿色化学
·
生物质转化
✓ 已验证
产品关联
DOI
高影响因子
RARE METALS
·
2025
·
IF 11
Gu Jia-Min,Kim Hyunmin,Zhao Ju-Zheng,Wang Yu-Qi,Zhao Yun-Xia,Ye Cai-Chao,Bu Yun-Fei
Advancing clean energy technologies demands efficient and durable electrode catalysts for solid oxide cells (SOCs). Despite their exceptional catalytic properties, Pt-based materials face critical challenges in high-temperature applications owing to particle agglomeration and cost constraints. Here, we demonstrate a rational design strategy utilizing controlled in situ exsolution to create strongly anchored PtSn nanoalloys on oxygen-deficient PrBaMn 1.8 Pt 0.1 Sn 0.1 O 5+ δ (L-PBMPtSn) perovskite oxide. Through precise compositional engineering and structural control, we achieved a uniform dispersion of PtSn nanoparticles with unique socket-like interfaces that prevent agglomeration while maintaining high catalytic accessibility. The optimized electrode demonstrates remarkable bifunctional performance, achieving a current density of 1.6 A cm −2 at 1.8 V for CO 2 electrolysis and a maximum power density of 316 mW cm −2 for fuel cell operation at 800 °C. More significantly, the electrode exhibits exceptional stability with only 9.6% performance degradation over 100 h of operation, which is a substantial improvement over conventional electrodes. Our findings establish a new paradigm for designing high-performance SOC electrodes through the controlled exsolution of precious metal alloys, offering broader implications for catalyst design in high-temperature electrochemical systems. Graphical abstract
研究领域:
材料科学
·
能源技术
·
电化学
·
纳米技术
·
催化
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Zheqin Chen,Yongmin Xie,Zhibin Lu,Xiaocong Zhong,Zhifeng Xu
This research addresses the issue of particle agglomeration and a low catalytic activity in the traditional sol–gel preparation of LaNi 0.5 Co 0.5 O 3 (LNCO). A new synthetic strategy is proposed, leveraging the combination of polyvinylpyrrolidone (PVP) serving as a complexing agent and graphene nanosheet (GN) functioning as a template, successfully producing a high-activity LNCO cathode material (GN-LNCO) with a layered structure. Various characterizations confirmed that incorporating PVP and GN effectively suppressed particle agglomeration at high temperatures. The optimized GN-LNCO exhibited excellent physicochemical properties, including a specific surface area of 45.21 m 2 g −1 , a more regular mesoporous structure, a higher electronic conductivity, and a greater oxygen vacancy concentration. Electrochemical performance tests showed that the GN-LNCO cathode demonstrated an outstanding performance in solid oxide fuel cells at 800 °C, with a peak power density of 350.91 mW cm −2 . This represented an improvement of 28.65% over the conventional LNCO. Additionally, a 72 h long-term stability test of a GN-LNCO single cell revealed a voltage decay rate of only 1.60%, indicating its excellent stability. Overall, this study provides a novel material design strategy for developing high-performance cathodes, which has significant implications for advancing solid oxide fuel cell technologies.
研究领域:
材料科学
·
电化学
·
能源技术
·
纳米技术
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
·
2021
·
IF 2.328
Pan Yang,Chunhui Yue,Yingnan Yang,Jingchuan Wang,Yawei Hao,Heshun Huang,Jing Zhu,Guozong Yue,Xiaochong Zhao,Lijun Yang
Transition metal compounds, as promising non-precious metal-based materials for hydrogen evolution reaction, have been limited by metal particles agglomeration. It is challenging to achieve ultra-dispersion of transition nano-metal catalysts, which would enlarge surface areas and reinforce physical stability. In this study, self-supported, highly dispersed NiMo nanobelts have been prepared by electrospinning and in-situ vacuum reduction. The unique belt structure with large active sites could facilitate the electron transfer and exhibits sufficient mechanical strength. The NiMo nanobelts show excellent HER activity, which achieve 10 mA cm −2 in 1 M KOH only required 62 mV overpotential, as well as great cycling stability.
研究领域:
材料科学
·
电化学
·
纳米技术
·
催化
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）