FERROELECTRICS
·
2018
·
IF 0.728
Yuguo Zhuo,Jun Liu,Qingshan Li
Nano-TiO2/MDI-50 based waterborne polyurethane composites were prepared with MDI-50, polypropylene glycol (PPG) and nano-TiO2 as main materials. Nano-TiO2 was modified using r-aminopropyltriethoxysilane (KH550) as modifier in order to improve the dispersion of nano-TiO2 in WPU. The composites morphologies and physical states were investigated using scanning electron microscopy (SEM), thermogravimetry analysis (TG), fourier transform infrared (FTIR) spectroscopy and UV-visible (UV-Vis) spectroscopy. Scanning electron microscopy observations revealed that modified nano-TiO2 has good dispersibility. Results from FTIR and TG suggested that the modified nano-TiO2 had been successfully introduced to the polyurethane molecular chain and the thermal decomposition temperature of nano-TiO2/MDI-50 based waterborne polyurethane composites doubled under the same thermal weight loss. Results from UV-Vis suggested that when 2% of modified nano-TiO2 was added, maximum absorbance of composites were significantly improved and was twice higher than that of pure waterborne polyurethane.
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
Journal of Energetic Materials
·
2022
·
IF 2.421
Shu-Ji Wang,Di Wang,Ping Liu,Xiao-le Sun,Shi Yan,Xue-Yong Guo
TKX-50, as a representative of a new nitrogen-rich energetic compound, has attracted extensive interests due to its high energy and low sensitivity properties. As an important energetic material, combustible agent has great influence on improving the energy level of explosives and propellants. Boron powder has become the most potential combustible agent in energetic fields because of its unique performances. In this work, nano-boron-based microspheres containing TKX-50 are directly fabricated by electrospray deposition. The prepared microspheres showed high monodispersity with particle size ranging from ~1–3 μm. Thermal behavior results show that the mass gain of the electrostatically sprayed sample is 163.3%, which is much higher than that of pure boron and physically mixed samples. Combustion behavior tests show that electrosprayed microspheres exhibit outstanding performance in comparison to physical mixed sample, the peak pressure improved by 85%, the burning time decreased by 21% and the pressurization rate improved by 136%. These excellent properties are probably related to their uniform microstructure. Therefore, electrospray preparation of microspheres with controllable structure has a good application prospect in energetic materials.
研究领域:
化学
·
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Bangjian Liu,Hong Yang,Huiqing Xu,Quanjie Liu,Shuandi Hou,Anfeng Zhang,Xinwen Guo
Effective regulation of acid sites is essential to strengthen the reaction performance and to modulate product distribution of an isomerization reaction. In this study, ZSM-50 (Al-EUO) and Fe-substituted ZSM-50 zeolites, namely FeAl-EUO-n (n = 0.25, 0.50 and 0.75) and Fe-EUO, are synthesized by a seed-assisted hydrothermal method. The study has shown that Fe has effectively entered the Al-EUO framework as a tetrahedrally-coordinated species. More importantly, the Fe-substitution has resulted in a significant increase in the amount of surface weak- and medium-strength Brönsted acids and a reduction in the strength of strong acids of FeAl-EUO-n. This study also evaluates the catalytic performance of Pt/FeAl-EUO-n catalysts in n-heptane hydroisomerization. It shows that the introduction of Fe in ZSM-50 greatly enhances the isomer yield, achieving a maximum yield of 66.1 % at 320 °C over Pt/FeAl-EUO-0.50 compared to 16.4 % at 300°C over Pt/Al-EUO. At the same time, the fraction of multi-branched iso -heptane also increases noticeably in the reaction product.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ORGANIC PROCESS RESEARCH & DEVELOPMENT
·
2024
·
IF 3.1
Shichun Weng,Juan Zhou,Yingtao Tian,Xigui Jiang,Rong Chen,Jinyao Hu,Zichao Guo,Liping Chen,Wanghua Chen
In this article, a mixture of sulfuric acid and 50% hydrogen peroxide solution was used to produce Caro’s acid, which serves as an oxidant frequently encountered in the fine chemical industry. The chemical compatibility between 50% H2O2/H2SO4 and organic solvents is an important safety issue. The compatibility of 50% H2O2/H2SO4 and several organic solvents, including ethanol, acetonitrile, ethyl acetate, DMF, dichloroethane, DMSO, ether, and toluene, was studied by reaction calorimetry and thermal analysis techniques. It was found that the first five solvents presented good compatibility with 50% H2O2/H2SO4. DSC tests indicated that these five solvents almost did not react with 50% H2O2/H2SO4 before the onset decomposition temperature of 50% H2O2/H2SO4 (∼93.3 °C). RADEX tests showed that the reactions of 50% H2O2/H2SO4 with these solvents released heats from 800 to 1100 J g–1, and the pressure effect was obvious for these mixtures. In contrast, the last three solvents, namely, DMSO, ether, and toluene, were incompatible with 50% H2O2/H2SO4, exhibiting a significant exothermic signal at lower temperatures. Most interestingly, the mixture of DMSO and 50% H2O2/H2SO4 presented a thermal runaway phenomenon below 40 °C. The causes of this thermal runaway incident were confirmed to be the oxidation of DMSO by Caro’s acid. Reaction calorimetry tests also indicated that the oxidation rate of DMSO was fast even at 40 °C, and the adiabatic temperature rise for the oxidation of DMSO was higher than 400 K.
研究领域:
化学工程
·
安全科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2024
·
IF 3.7
Lei Xiao,Xinfei Wang,Tianfu Zhang,Xiaojun Feng,Kun Zhang,Junqing Yang,Xiaoming Jin,Gazi Hao,Wei Jiang
In order to achieve new energetic materials with high energy, low sensitivity, and moisture-proof properties, dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50)/ammonium perchlorate (AP) cocrystal (molar ratio 1:1) was successfully prepared through a spray-assisted solvent–nonsolvent method. SEM shows that the morphology of the cocrystal is different from those of the two raw materials. XRD and FT-IR spectra indicate the formation of the cocrystal. The apparent activation energy of the cocrystal is lower than that of raw TKX-50. The characteristic drop height (H50) is higher than that of TKX-50, while the friction sensitivity (P) of the cocrystal is lower. In addition, the moisture-proof property of the cocrystal is improved, showing good application potential.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2020
·Vol. 143
·期 4
·3003-3008
·
IF 2.731
Li Xiaoxia,Cao Xiong,Bai Xueyuan,Pei Zhinan,Deng Peng,Hu Shuangqi
In the article, we reported two-dimensional nanoscale MoS 2 has been demonstrated to possess intrinsic catalytic activity for thermal decomposition of dihydroxylammonium-5,5′-bistetrazole-1,1′-diolate (TKX-50). The morphology and structure of MoS 2 nanosheets prepared by liquid ultrasonic exfoliation were characterized by scanning electron microscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectra. Thermal catalysis decomposition was investigated by thermogravimetric/differential scanning calorimetry. MoS 2 was added to TKX-50, and the results show that nano-MoS 2 can decrease the activation energy of TKX-50 decomposition from 220.0 to 140.6 kJ mol −1 effectively and that the decomposition temperature was decreased by 32.1 °C more than 23.8 °C for commercial bulk MoS 2 . In addition, a possible mechanism of MoS 2 towards the catalysis thermal decomposition of TKX-50 was proposed. The conduction-band electrons ( e
− cb
) and valence-band holes ( h + ) excited on the surface of MoS 2 under thermal excitation promoted H + transfer from H atom of NH 3 OH + to O atom of bisteterazole and boosted the decomposition of TKX-50 further. This work may offer a new idea to introduce transition metal dichalcogenide into thermal catalysis fields.
研究领域:
材料科学
·
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2019
·Vol. 44
·期 4
·413-422
·
IF 1.634
Wenbo Dong,Shusen Chen,Shaohua Jin,Minglei Chen,Bo Yan,Yu Chen
Dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) is an energetic ion salt with high energy and low mechanical sensitivity. However, its poor morphology and low binding ability with conventional binders have significantly limited its application. In the present work, we reported a novel strategy to improve the morphology and surface properties of TKX-50 using sodium alginate (SA) as the modifier by the anti-solvent method. The results of imaging characterization indicated that SA greatly affected both crystal habit and morphology of TKX-50, resulting in modified TKX-50 granulars with low aspect ratios. The formation mechanism was explored by the molecular dynamics simulation. The XPS and SEM characterizations also revealed that SA adhered onto TKX-50 surface to form a coating layer. The non-isothermal kinetic parameters were calculated from DSC results. Our work has provided a new strategy to improve the morphology and surface properties of TKX-50 for its practical applications.
研究领域:
材料科学
·
爆炸化学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2023
·
IF 4.6
Shu-ji Wang,Di Wang,Peng Chen,Shi Yan,Qing-jie Jiao,Xue-yong Guo
Micro-nano composite energetic materials have attracted extensive attention from researchers due to their excellent properties. Electrostatic spray drying, as an emerging composite material preparation technology, has an important impact on the assembly and energy release regulation of energetic materials. In this paper, NC with excellent mechanical properties was selected as the energetic binder. The uniform assembly of TKX-50 and Al was achieved by electrostatic spraying technology, and Al@TKX-50@NC micro-nano composite energetic material microspheres were prepared. The structure and composition of the composite were characterized, and its thermal decomposition kinetics and thermodynamics were calculated and analyzed. At the same time, its ignition and combustion performance were tested. It is found that the samples prepared by electrostatic spray are regular spherical, and the particle size is about 1–6 μm. Compared with the physical mixture samples, the Al@TKX-50@NC composite microspheres not only have a more complete oxidation reaction but also have better ignition and combustion performance. The results show that the electrostatic spray method is very effective in improving the energy release of composite energetic materials.
研究领域:
材料科学
·
能量材料工程
✓ 已验证
产品关联
DOI
高影响因子
FirePhysChem
·
2021
·
IF 0
Chao Chen,Haijian Li,Jianhua Yi,Zhao Qin,Changjian Wang,Zhihua Sun,Yi Xu,Siyu Xu,Kangzhen Xu,Fengqi Zhao
Two novel heterobimetallic metal-organic frameworks (MOFs), Ba 4 Pb 4 (CH 3 CO 2 ) 8 [(CH 6 CO 2 ) 4 Pb](CH 3 CO 2 ) 4 (PbBa-MOFs) and Ba 2 Ni(CO 2 H) 6 (OH 2 ) 4 (NiBa-MOFs), were prepared via the solvothermal method, and their structures were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. The pyrolysis behavior of the two MOFs and their catalytic performances on the dihydroxylammonium-5,5’-bistetrazole-1,1’-diolate (TKX-50) pyrolysis were studied by thermogravimetric-differential scanning calorimetry (TG-DSC) and thermogravimetric-fourier transform infrared spectroscopy-mass spectrum (TG-FTIR-MS) methods. Compare with the pure TKX-50, the pyrolysis peak temperature and apparent activation energy ( E a ) of the TKX-50/PbBa-MOFs mixture were decreased by 3.2°C and 13.47 kJ‧mol −1 respectively. The E a of TKX-50/NiBa-MOFs was decreased by 9.35 kJ‧mol −1 . And the second pyrolysis peak disappeared in the DSC curves of TKX-50 after the addition of the two MOFs, due to that the products from MOFs pyrolysis suppress the chemical reaction pathway on the production of 5,5′-bis (2-hydroxytetrazole) (ABTOX) and accelerate the direct decomposition of 1,1’-bistetrazole diol (BTO). This resulted in the percentage of H 2 O decreased greatly and the percentage of NO/CH 2 O, CO 2 /N 2 O, NH 2+ /O• and NH 3 /OH increased during the pyrolysis of TKX-50. Finally, the relation between the pyrolysis and ignition characteristics was discussed and described. The two MOFs reduced the ignition delay time of the TKX-50 at the high power density region, and the flame becomes more luminous due to the formation of metal oxides and active free radical.
研究领域:
材料科学
·
化学
·
能源化学
✓ 已验证
DOI
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Yong Chen,Ming Zhang,Hui Li,Zhao Qin,Fengqi Zhao,Heng Li,Kangzhen Xu
In order to develop efficient combustion catalysts for solid propellants , three intermetallic compounds of Sn-Cu, Sn-Co and Sn-Ni were synthesized by a hydrothermal method and their effects on the thermal decomposition and ignition properties of 1,3,5-trinitroperhy-dro-1,3,5-triazine (RDX) and 5,5′-bistetrazole-1,1′-diolate (TKX-50) were studied systemically. The results show that Sn-Cu, Sn-Co and Sn-Ni can all promote the thermal decomposition of RDX, which reduce the exothermic decomposition peak temperature of RDX by 3.2, 1.9 and 4.8 ℃, respectively. And the apparent activation energy of RDX was reduced by 82.1 kJ·mol −1 after adding the Sn-Ni intermetallic compound. In comparison with RDX, the exothermic peak temperature of TKX-50 was reduced more significantly, which was decreased by 11.9, 1.5 and 6.6 ℃ in the existence of Sn-Cu, Sn-Co and Sn-Ni, respectively. Additionally, Sn-containing intermetallic compound could reduce the ignition delay time of RDX under high power laser density, while the ignition delay time of TKX-50 could be decreased in the full power density range of the experiment. Besides, the flame combustion intensity and propagation rate of RDX and TKX-50 were significantly heightened by adding the three compounds. The comparison of pyrolysis and ignition performance before and after adding Sn-containing intermetallic compound into RDX and TKX-50 shows that Sn-containing intermetallic compound has great application prospects for improving the heat release and combustion characteristic of solid propellants.
研究领域:
材料科学
·
燃烧与推进
·
化学动力学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
·
2021
·
IF 4.291
Jian-Bo Chen,Taishan Yan,Chaofeng Wang,Ruixia Gao,Silong Xu,Guijuan Fan,Xueyan Zhao,Yu Liu
The dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50), as an outstanding representative of nitrogen-rich energetic salts, has recently attracted increasing interest due to its excellent performances. However, it is unclear about the photostability and degradation pathways of TKX-50 in aqueous solution. In this paper, the photostability and the degradation process of TKX-50 in aqueous solution have been comprehensively studied for the first time. TKX-50 can keep stable toward visible light. However, it presented a rapid degradation with rate constant of 0.0054 s −1 under 254-nm light irradiation. TKX-50 also demonstrated much faster photodegradation than traditional nitro explosives. Further, degradation products of TKX-50 were analyzed by high-resolution mass spectrum with theoretical calculations. The photodegradation pathways are proposed that 5,5′-bistetrazole-1,1′-diolate (BTO) anion of TKX-50 can been fragmented into the nitrile by losing N 2 and HNO, and then hydroxylammonium (NH 3 OH + ) from TKX-50 reacts with the nitrile through the nucleophilic addition. Besides as a solvent, water also may accelerate the photodegradation of TKX-50 probably by hydrolyzing the intermediary nitrile products. In a word, this study provides comprehensive understanding about the photostability of TKX-50 in aqueous solution, and it is helpful to study the photochemistry of other energetic ionic salts based on BTO.
研究领域:
化学
·
材料科学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2023
·
IF 6.6
Liang Tan,Yijin Wu,Deliang Cheng,Renzong Hu
High-capacity storage in Li-ion batteries with graphite anodes remains a challenge at low temperature. By contrast, metal-based composite anode materials, including Sn metal, have shown good lithium storage capabilities at low temperature. However, the suitable low temperature electrolyte is still infancy to achieve high efficiency capacity of Sn-based anode in ultra-low temperature. Herein, a 2-methytetrahydrofuran (2Me-THF)-based low temperature electrolyte is proven to support the excellent lithium capability of Sn-based anode at ultra-low temperatures. The formulated 2Me-THF electrolyte exhibited small changes in viscosity and ionic conductivity with decreasing temperature. A SnO 2 -LiF-G (graphite) electrode with 1 M lithium bis(trifluoromethanesulfonyl)imide-(2Me-THF) electrolyte maintained 80% of the room temperature reversible capacity at -30°C and delivered a reversible capacity of 650 mAh g −1 , even at -50°C, under a current density of 100 mA g −1 . Furthermore, a detailed characterization based on Fourier Transform Infrared Spectroscopy, X-ray Photoelectron Spectroscopy and Time-of-flight Secondary ion Mass Spectrometry confirmed that the formed inorganic-rich solid electrolyte interphase on the electrode surface effectively maintained the solid-liquid interfacial stability at low temperature. This work provided design concepts for ultralow temperature electrolytes for metal-based anodes, which were especially helpful for further promoting batteries for low temperature applications.
研究领域:
材料科学
·
电化学
✓ 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）