CHEMISTRY OF MATERIALS
·
2025
·
IF 7
Bangjian Liu,Hong Yang,Limin Ren,Zhaoyang Song,Quanjie Liu,Shuandi Hou,Anfeng Zhang,Xinwen Guo
In this study, a rapid synthesis of ZSM-50 zeolites is achieved by a two-step aging–crystallization hydrothermal method. By optimizing the temperature/time for aging (393 K/48 h) and crystallization (423 K/72 h), the synthesis time for obtaining pure-phase ZSM-50 zeolites has been significantly shortened to 4 days from typically weeks. The gel compositions to form pure-phase ZSM-50 have also been mapped out in the ternary composition diagram of 5Al2O3/SiO2–OSDA/SiO2–OH–/SiO2 under the optimized aging–crystallization conditions. Furthermore, three ZSM-50 samples are synthesized using different gel compositions and/or crystallization conditions. The samples have different acidity characteristics and average crystal sizes from 5 to 17 μm. As catalysts for n-heptane hydroisomerization, the three Pt-loaded ZSM-50 catalysts deliver the maximum iso-heptane yield directly correlated to their surface weak Brönsted acid sites on the external surface. The ZSM-50 (5 μm) catalyst has a superior catalytic activity, achieving a maximum iso-heptane yield of 71.4% at 543 K, along with a high fraction of multibranched isomers of 29.1%. This study highlights the pivotal role of particle size in modulating acid properties and pore accessibility in ZSM-50 and offers a facile strategy for designing effective bifunctional catalysts for n-alkane isomerization.
研究领域:
材料科学
·
化学工程
·
催化
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2019
·Vol. 141
·期 4
·1413-1423
·
IF 2.471
Zhang Ming,Zhao Fengqi,Yang Yanjing,Li Hui,Gao Hongxu,Yao Ergang,Zhang Jiankan,An Ting,Jiang Zhoufeng
Bimetallic iron oxides (NiFe 2 O 4 , ZnFe 2 O 4 and CoFe 2 O 4 ) were prepared via the facile solvothermal method and characterized using SEM, TEM, XRD, FTIR, XPS and BET instruments. The catalytic behavior of the bimetallic iron oxides on the thermal decomposition of 5, 5′-bistetrazole-1, 1′-diolate (TKX-50) was studied using DSC and TG-DTG methods. Besides, the corresponding kinetic parameters of TKX-50 thermal decomposition were calculated by multi-kinetics methods including traditional, iso-conversional and iteration methods. The thermal decomposition peak temperature ( T p ) and the activation energy ( E a ) reduced obviously after the addition of bimetallic iron oxides. Among different bimetallic iron oxides, the ZnFe 2 O 4 has the best catalytic activity for TKX-50 thermal decomposition. The high thermal decomposition peak temperature ( T HDP ) and average apparent activation energy ( E a ) of TKX-50 were decreased by 47.0 °C and 34.34 kJ mol −1 in the presence of ZnFe 2 O 4 sample. The excellent catalytic activity of ZnFe 2 O 4 for thermal decomposition of TKX-50 makes it a promising combustion catalyst of insensitive solid propellants containing TKX-50.
研究领域:
材料科学
·
燃烧与推进
·
物理化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2024
·
IF 4
Zhen Zhang,Fengqi Zhao,Ming Zhang,Yifan Jiang,Zhao Qin,Wengang Qu,Chao Chen,Jiankan Zhang
The carbon dots (CDs) were obtained by oxidation etching of coal pitch powder with peroxic acid. The CDs/Fe 2 O 3 composites were in-situ prepared by hydrothermal method. The composition, morphology and structure of CDs and CDs/Fe 2 O 3 were analyzed by TEM/HRTEM, XRD, EDS and XPS. The effects of CDs, Fe 2 O 3 and CDs/Fe 2 O 3 on the thermal decomposition of TKX-50 were studied by DSC-MS-FTIR and in-situ-solid FTIR. The three materials decreased the peak temperature of TKX-50 by 12.1, 33.9 and 39.0℃ (under the warming rate of 10℃·min −1 ). The CDs/Fe 2 O 3 showed best catalytic performance. The carboxyl group contained on the surface of CDs adsorbed NH 3 , inhibiting the formation of by-decomposition products ABTOX. Besides assimilating NH 3 and restraining the agglomeration of Fe 2 O 3 , the CDs/Fe 2 O 3 provided more active sites for decomposition which reduce the decomposition and activation energy of TKX-50 and promoted the reaction. Furthermore, CDs/Fe 2 O 3 reduced the ignition delay time of TKX-50 and significantly increased the flame propagation speed and flame area. Therefore, CDs and its compound CDs/Fe 2 O 3 have excellent application prospects in solid propellant combustion catalysts.
研究领域:
材料科学
·
化学工程
·
燃烧学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2024
·
IF 5.8
Ming Zhang,Fengqi Zhao,Hexin Liu,Na Li,Yifan Jiang,Zhen Zhang,Hui Li,Zhao Qin
Novel graphene iron tannate and graphene iron gallate nanocomplex (G-D-Fe and G-M-Fe) were designed, prepared and characterized by SEM , EDS , FTIR, RAMAN and XPS equipment. The catalytic property of the G-D-Fe and G-M-Fe for energetic TKX-50 was explored by DSC , kinetic calculation and laser ignition. The synthesized G-D-Fe and G-M-Fe present a positive impact on pyrolysis and ignition combustion of TKX-50, resulting in the significantly reduced decomposition temperature , activation energy ( E a ) and ignition delay time. After adding G-D-Fe (G-M-Fe), the first and second decomposition peak temperatures ( T FDP and T SDP ) of TKX-50 were decreased by 42.3 °C (43.9 °C) and 45.0 °C (49.6 °C), respectively. At the conversion degree of 0.2–0.8, the nonlinear kinetic data showed that after adding G-D-Fe and G-M-Fe, the E a of TKX-50 decreased from 163.5 to 141.3 and 145.4 kJ·mol −1 respectively. Additionally, after adding G-D-Ni and G-M-Ni, the laser ignition delay time of TKX-50 was reduced from 58 ms to 26 ms and 28 ms, respectively. The possible catalytic mechanism of preferred combustion catalyst G-D-Fe was disclosed by in-situ FTIR and gas-phase MS-FTIR analysis. The results are helpful to broaden the catalysts for pyrolysis and ignition combustion of TKX-50 and to disclose the catalytic mechanism.
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
Catalysts
·
2021
·Vol. 11
·期 4
·499
·
IF 4.146
Tiefeng Wang,Xu Li,Xiaosheng Zhang,Jinxiang Dong
Dimethyl-carbonate (DMC) is a green carboxymethylation agent for synthesis of the versatile long-chain alkyl carbonates through base-catalyzed transesterification with aliphatic alcohols. Herein, we demonstrated the facile preparation of a novel heterogeneous base catalyst α-KMgPO4using commercially cheap metal salts via hydrothermal-calcination procedure. The combination of temperature programmed desorption (TPD) and FTIR measurements with CO2pre-adsorbed revealed the presence of weak and medium base sites on α-KMgPO4. Furthermore, α-KMgPO4catalyzed transesterification of DMC and n-octanol was performed in a sealed-vessel reactor (Monowave 50). The results show that the reaction was completed in only 10 min with the 97.5% conversion of n-octanol and >99% selectivity to asymmetric methyl-octyl carbonate under the optimal conditions. Additionally, the possible catalytic mechanism is proposed. As an extended contribution, the tribology performance of the asymmetric methyl-alkyl carbonates was further evaluated.Keywords:catalyst;α-KMgPO4;transesterification;asymmetric carbonates;Monowave 50 reactor
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energetic Materials
·
2019
·
IF 1.649
Wenbo Dong,Shusen Chen,Shaohua Jin,Yu Chen
Dihydroxylammonium 5,5ʹ-bistetrazole-1,1ʹ-diolate (TKX-50) is an energetic ionic salt with excellent properties of low mechanical sensitivity, environment-friendliness, and low toxicity. It meets the requirement of high insensitivity for military high-energy explosives. However, the poor crystal habit of TKX-50 in most solvents, as well as its poor adhesive ability with conventional binders, has limited its application. In the present work, we report a novel strategy to improve the morphology and surface property of TKX-50 using an environmentally friendly anionic polyelectrolyte, carboxymethylcellulose sodium (CMC), by the anti-solvent method. The scanning electron microscope analysis indicates that the morphology of TKX-50 was greatly altered in the presence of CMC, resulting in TKX-50 granules with low aspect ratios. Molecular dynamics simulation was conducted to explore the mechanism of such morphological change. It was found that the combined action of ethanol and CMC promoted the growth of (110) and (011), while the (020) still dominated the crystal growth, resulting in the low aspect ratio of TKX-50. The effects of CMC coating on the particle size of TKX-50 and the interaction between CMC and TKX-50 were investigated with the focused beam reflectance measurement and particle video microscope. Further characterization suggested that the highest coating efficiency (R) could be obtained at the CMC content of 4% with which granular TKX-50 crystals were produced. The non-isothermal kinetic study revealed that the CMC coating also improved the thermal stability of TKX-50. Our work has provided a novel method to improve the properties of TKX-50 for its practical application.
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
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2019
·Vol. 140
·期 4
·1759-1767
·
IF 2.471
Zhang Jiankan,Zhao Fengqi,Yang Yanjing,Yan Qilong,Zhang Ming,Ma Wenzhe
Fe 3 O 4 /reduced graphene oxide (Fe 3 O 4 /rGO) nanocomposite has been successfully fabricated using a modified interface solvothermal method and characterized by X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. In the preparation procedure, graphene oxide was reduced and ultrafine Fe 3 O 4 nanoparticles (NPs) were uniformly loaded on reduced graphene oxide (rGO) carrier. Scanning electron microscope, transmission electron microscope images and Brunauer–Emmett–Teller specific surface area revealed that the aggregation of Fe 3 O 4 NPs was greatly reduced by introducing rGO as a substrate. The average size of the Fe 3 O 4 NPs anchored on the graphene sheets was 100 nm, which is much smaller than 1-μm bare Fe 3 O 4 . The DSC results showed that Fe 3 O 4 /rGO nanocomposite reduces the first decomposition temperature of dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) by 44.9 °C and decreases the apparent activation energy of TKX-50 by 26.2 kJ mol −1 , which exhibits higher catalytic performance than its individual components and their physical mixture (hybrid). Hence, Fe 3 O 4 /rGO nanocomposite can be a promising additive for insensitive solid propellants based on TKX-50.
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
Materials Today Communications
·
2023
·
IF 3.8
Zhen Zhang,Zhao Qin,Ming Zhang,Yifan Jiang,Chao Chen,Jiankan Zhang,Fengqi Zhao
The carbon dots (CDs) were prepared by the oxidation etching method. On this basis, the composite materials of CDs and Cu (CDs/Cu) were synthesized by the hydrothermal method . The elemental composition, morphology and structure were analyzed by TEM, SEM, EDS , XRD and XPS . The effects of CDs and CDs/Cu for thermal decomposition of TKX-50 pyrolysis were studied by DSC-FTIR-MS and in-situ solid FTIR . The CDs and CDs/Cu reduced the low-temperature decomposition peak temperature of TKX-50 by 10.1 ℃ and 16.1 ℃ respectively (10 ℃·min −1 ), and the second decomposition peak almost disappeared. This is because CDs and CDs/Cu can effectively facilitate the thermal decomposition of TKX-50 into NH 2 OH and 1,1′-ditetrazole diol (BTO). The CDs can promote the direct decomposition of BTO into small molecule gases and stable polymers at the initial pyrolysis stage. And they inhibit the combination of BTO and NH 3 into 5,5′-bistetrazole-1,1′-didiolate (ABTOX), which is more difficult to decompose. So, the HCN and N 2 /CO were increased obviously during pyrolysis while NH 3 and H 2 O content were decreased. On the other hand, the CDs/Cu promotes the decomposition of NH 2 OH in the first reaction. It manifested as the increase of NH 3 and H 2 O. At the same time, the CDs/Cu facilitates the transition of difficult to decompose ABTOX losing NH 3 to BOX to accelerate thermal decomposition reaction , playing a synergistic catalytic effect. Thus, in-situ solid FTIR signal of ABTOX was significantly weakened and the total content of NH 3 was raised, especially the significant expansion of NH 3 in the second stage. Finally, the influence of the catalysts in ignition characteristics was contrasted and discussed. Under the lower-power density region, the CDs and CDs/Cu decreased the ignition delay time of TKX-50. The CDs/Cu caused the flame propagation velocity of TKX-50 faster. Therefore, the CDs and their composites, as another new lightweight carbon material, are expected to be applied in the catalytic combustion of energetic materials.
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 PHYSICS AND CHEMISTRY OF SOLIDS
·
2021
·
IF 3.995
Chao Chen,Haijian Li,Zhao Qin,Changjian Wang,Yi Xu,Zhihua Sun,Siyu Xu,Jianhua Yi,Fengqi Zhao
Hexanitro complex K 2 Ba[Ni(NO 2 ) 6 ] was prepared via the co-precipitation method, and its composition and morphology were characterized by XRD , SEM , XPS and FT-IR techniques. The catalytic performances of K 2 Ba[Ni(NO 2 ) 6 ] for CL-20, FOX-7 and TKX-50 thermolysis were also discussed and studied by using DSC and TG-DTG-MS. After K 2 Ba[Ni(NO 2 ) 6 ] were mixed with CL-20, the activation energy ( E a ) of thermolysis reaction was increased, while the heat release was greatly improved, and the transformation from NH 3 to NO occurred. It is attributed to that the decomposition products of K 2 Ba[Ni(NO 2 ) 6 ] have strong effects on the oxidation of the radicals and the electrons transfer . Besides, the thermolysis E a of FOX-7 by addition of the K 2 Ba[Ni(NO 2 ) 6 ] was increased by 81.03 kJ mol −1 , and the heat release was greatly increased. In addition to that the two-step separate thermolysis processes of pure FOX-7 was almost replaced by a one-step exothermic reaction for the FOX-7/K 2 Ba[Ni(NO 2 ) 6 ] mixture, which was due to that Ni 2+ cations could effectively increase the activity of amino groups in the FOX-7 thermolysis process. Finally, K 2 Ba[Ni(NO 2 ) 6 ] scarcely has the thermolysis catalytic activity of TKX-50 owing to the influence of metal cations on the decomposition of the hydroxylamine . Furtherly, the characteristics of ignition and flame propagation on the three energetic mixtures were strongly correlated to their thermolysis pathway and mechanism. The comparative study on the effects of K 2 Ba[Ni(NO 2 ) 6 ] to the CL-20, FOX-7 and TKX-50 thermolysis and ignition showed that the hexanitro complex has great significance on promoting the heat release efficiency of solid propellants for future study.
研究领域:
材料科学
·
化学动力学
·
含能材料
·
催化化学
·
热分析
✓ 已验证
DOI
高影响因子
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
·
2021
·
IF 3.995
Ming Zhang,Fengqi Zhao,Yanjing Yang,Hui Li,Ting An,Jiankan Zhang
rGO-Fe 2 O 3 nanocomposites with spherical, hollow and fusiform Fe 2 O 3 (s, h and f) microstructures have been successfully fabricated using DMF as solvent via a facile solvothermal method. The morphologies and compositions of the as-synthesized rGO-Fe 2 O 3 (s, h and f) nanocomposites were systematically studied using SEM, TEM , XRD , FTIR, RAMAN and XPS analysis . The rGO-Fe 2 O 3 (s, h and f) nanocomposites were used to catalyze the thermal decomposition of energetic TKX-50 and the corresponding kinetic parameters were calculated using an isoconversional model. The catalytic performance of Fe 2 O 3 (s, h and f) during the thermal decomposition of TKX-50 was significantly improved after being anchored onto the surface of graphene oxide . The as-synthesized rGO-Fe 2 O 3 (h) and rGO-Fe 2 O 3 (s) nanocomposites have an excellent effect toward reducing the temperature and apparent activation energy ( E a ) for TKX-50 decomposition, respectively. The excellent catalytic performance of rGO-Fe 2 O 3 (h) nanocomposite can be attributed to its external and internal surfaces, which provide more active sites for TKX-50 decomposition. In addition, the interactions formed between rGO and Fe 2 O 3 have a positive effect toward reducing the E a .
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
Chemical Biology & Drug Design
·
2025
·Vol. 106
·期 6
·e70214
·
IF 3.3
Guihua Jia,Jiayi Li,Abbas Khan,Aman Chandra Kaushik,Diyi Wu,Hongyu Chen,Rongpei Li,Jian Wang,Chen Zhang,Adil Farooq,Xueying Mao,Aamir Mehmood,Weidong Zhang,Heng Wang,Dong-Qing Wei
WGX-50, a previously reported drug candidate for Alzheimer's disease, is derived from Zanthoxylum bungeanum Maxim commonly called Sichuan pepper. Its pharmacological actions for the long run benefit of human health have been extensively investigated. However, in terms of its anti-aging effect, it totally remains unexplored. In this work, WGX-50 was first reported to promote healthy aging in Caenorhabditis elegans with insights from drug target prediction and molecular dynamics simulations. Further investigations have experimentally demonstrated that: Firstly, both daf-16 and skn-1 genes are causative to WGX-50 mediated longevity. WGX-50 failed to extend lifespan upon depletion of these genes in transgenic worms. Their orthologs Foxo1 and Nrf2 were also activated even in D-galactose (D-gal) induced aging and Zmpste24 −/− progeria mice intestines. Secondly, WGX-50 inhibits IIS signaling via downregulating daf-2 , and activating daf-16 and skn-1 genes, which thus enable downstream pro-longevity effectors increasing stress resistance and promoting healthier aging. WGX-50 increased expression levels of sod-3 , ctl-1 , gst-7/8/12/33 , gsto-1 , and heat shock protein genes such as hsp-12.2 , hsp-90 , F44E5.4/0.5 , T05E11.9 and their inducer hsf-1 . In addition, the accumulation of lipofuscin, fat, and reactive oxygen species levels with age was decreased significantly upon WGX-50 supplementation without physiological impairments. Thirdly, in progeria, D-gal and naturally aged mice, WGX-50 is incapable of inducing aging. Senescent genes and SASP factors were not produced at higher levels in livers and small intensities. No impact was observed on key organ indices, blood biochemistry parameters, and bone histomorphometry. WGX-50 perhaps prolongs lifespan through other mechanisms such as reducing fertility, inducing dietary restriction, and improving proteostasis with lowered levels of polyQ35 aggregates. Our findings thus provide primary insights for the potential medical use of WGX-50 in anti-aging and long-term healthcare.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2023
·
IF 3.9
Ruijuan Wang,Chunliu Ma,Haitao Yan,Pu Wang,Shuyan Yu,Tongyan Zhang,Zhigang Yin
Co-encapsulated xanthoxylin (GX-50) and vitamin C (Vc) microcapsules (GX-50-Vc-M) were prepared by the combination of a water-in-oil-in-water (W1/O/W2) double emulsion with complex coacervation. The W1/O/W2 double emulsion was prepared by two-step emulsification, and it has a uniform particle size of 8.388 μm and high encapsulation efficiencies of GX-50 (85.95%) and Vc (67.35%) under optimized process conditions. Complex coacervation occurs at pHs 4.0–4.7, which has the highest encapsulation efficiency of GX-50 and Vc at pH 4.5. The complex coacervate with tannic acid solidifying (namely, wet microcapsules) has better mechanical properties and also enhances the ability of co-encapsulation of active ingredients. The resulting microcapsules by freeze-drying of wet microcapsules were characterized by UV–vis absorbance spectroscopy (UV–vis), Fourier infrared spectroscopy (FI-IR), confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), X-ray diffraction (XRD), 2,2-diphenyl-1-picrylhydrazyl (DPPH·) radical scavenging, and in vitro permeation measurements. Under optimal conditions, the encapsulation efficiency and drug loading of GX-50-Vc-M for GX-50 and Vc are, respectively, 78.38 ± 0.51 and 59.34 ± 0.56%, and 35.6 ± 0.68 and 29.8 ± 0.92%. A slight shift in the FTIR peak between single GX-50 or Vc and GX-50-Vc-M confirmed the successful co-encapsulation of GX-50 and Vc in microcapsules. GX-50-Vc-M has bridged irregular spherical aggregates, while GX-50 and Vc are, respectively, encapsulated in hydrophobic and hydrophilic cavities of microcapsules in an amorphous dissolved state. GX-50-Vc-M has the highest DPPH· radical scavenging rate of 62.51%, and the scavenging process of GX-50-Vc-M on DPPH· radicals is more in line with the pseudo-second-order kinetic equation model. Moreover, the in vitro permeation of GX-50 and Vc in GX-50-Vc-M can reach maximum values of 40 and 60%, respectively. This concludes that GX-50-Vc-M is a promising delivery system for the penetration of the antioxidant into the deeper layers of the skin for the antioxidant effect.
研究领域:
药剂学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）