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Wang X, Guo Z, Hu Y, Hao G, Zheng Q, Chen J, Yang J, Jiang W. Insights into the Mechanical-Structural-Energetic Responses of RDX Nanoparticles from Molecular Dynamics Simulation. J Phys Chem A 2024; 128:6668-6676. [PMID: 39106203 DOI: 10.1021/acs.jpca.4c03638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2024]
Abstract
When the particle size of energetic materials is reduced to the nanoscale, significant changes occur in their properties and behavior. In this work, compression processes of three RDX nanoparticles (A, B, and C) were simulated using ReaxFF-lg. The mechanical, structural, and energetic responses of RDX nanoparticles during compression were revealed and characterized. Simulations reveal that the compression process of the nanoparticles can be divided into three stages: elastic stage, primary damage stage, and sustained damage stage. The temperature increase rate in the elastic phase is much lower than in the primary damage phase. In addition, we found that the smaller nanoparticle B presents a smaller elastic modulus and compressive strength, and it has a slower rate of temperature increase during the primary damage phase. Compared to cuboidal nanoparticles (A and B), the spherical nanoparticle C tends to absorb less energy during the elastic stage and exhibits slower damage rate during the primary damage stage. This is a key factor contributing to the low sensitivity of spherical nanoparticles.
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Affiliation(s)
- Xiaohe Wang
- National Special Superfine Powder Engineering Research Center of China, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Zhiwei Guo
- National Special Superfine Powder Engineering Research Center of China, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Yubing Hu
- National Special Superfine Powder Engineering Research Center of China, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Gazi Hao
- National Special Superfine Powder Engineering Research Center of China, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Qilong Zheng
- Xi'an Modern Chemistry Research Institute, Xi'an 710065, China
| | - Jing Chen
- Xi'an Modern Chemistry Research Institute, Xi'an 710065, China
| | - Junqing Yang
- National Special Superfine Powder Engineering Research Center of China, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
- School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Wei Jiang
- National Special Superfine Powder Engineering Research Center of China, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
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Kazakov AI, Lempert DB, Nabatova AV, Gorbovskii KG, Chukanov NV, Ignatieva EL, Dashko DV, Yanovskiy LS. Thermal Stability of Trimolecular Cocrystallizate Based on Energy-Intensive Polynitramine CL-20 with H2O2 and H2O and its Efficiency in Solid Composites. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY B 2022. [DOI: 10.1134/s1990793122060173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Chukanov NV, Shilov GV, Ignat’eva EL, Dashko DV, Lempert DB, Kazakov AI, Aldoshin SM. Monoclinic Modification of Trimolecular Cocrystallizate of the High-Energy Polynitramine CL-20 with H2O2 and H2O: Synthesis and Structure. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY B 2022. [DOI: 10.1134/s1990793122050025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Zhao X, Li J, Quan S, Fu X, Meng S, Jiang L, Fan X. Study on the effect of solvent on cocrystallization of CL-20 and HMX through theoretical calculations and experiments. RSC Adv 2022; 12:21255-21263. [PMID: 35975069 PMCID: PMC9341422 DOI: 10.1039/d2ra03730k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 07/19/2022] [Indexed: 12/04/2022] Open
Abstract
Cocrystallization is a helpful method for explosives design. However, lack of understanding of the cocrystallization mechanism leads to inefficiency in cocrystal preparation. Therefore, studying the effects of solvent on cocrystal is of great importance for the efficient application of 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (CL-20). In this paper, the effect of solvent on cocrystallization is investigated by the CL-20/HMX cocrystal/solvent cluster model, the CL-20/HMX/solvent mixture model, the CL-20/HMX cocrystal/solvent interface model combined with quantum chemistry and molecular dynamic methods. The authors find that the hydrogen bond between CL-20 and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) is the strongest and the binding energy of cocrystal and solvent molecules is the weakest in ethyl acetate (EA) solvent, indicating that CL-20 and HMX tend to be combined together and there is less hindrance by solvent molecules. Analysis of the CL-20/HMX/solvent mixture and mass density distribution studies show that the solvent effect has a great influence on the crystal faces and the cocrystallization rate of CL-20 and HMX is the highest in EA solvent. The XRD and SEM characterization results are consistent with the theoretical calculations. The present work on the effects of solvent on CL-20/HMX cocrystals is beneficial for understanding the mechanism of the growth of energetic cocrystal materials. It is helpful in selecting more suitable theoretical and experimental conditions and makes access to excellent cocrystals more efficient. Cocrystallization is a helpful method for explosives design. Studying the effects of solvent on cocrystal is of great importance for the efficient application of CL-20/HMX cocrystal.![]()
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Affiliation(s)
- Xitong Zhao
- Xi'an Modern Chemistry Research Institute Xi'an 710065 Shaanxi China
| | - Jizhen Li
- Xi'an Modern Chemistry Research Institute Xi'an 710065 Shaanxi China
| | - Shuxin Quan
- Qingyang Chemical Industry Corporation Liaoyang 111001 Liaoning China
| | - Xiaolong Fu
- Xi'an Modern Chemistry Research Institute Xi'an 710065 Shaanxi China
| | - Saiqin Meng
- Xi'an Modern Chemistry Research Institute Xi'an 710065 Shaanxi China
| | - Liping Jiang
- Xi'an Modern Chemistry Research Institute Xi'an 710065 Shaanxi China
| | - Xuezhong Fan
- Xi'an Modern Chemistry Research Institute Xi'an 710065 Shaanxi China
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Lian P, Zhang L, Su H, Chen J, Chen L, Wang J. A novel energetic cocrystal composed of CL-20 and 1-methyl-2,4,5-trinitroimidazole with high energy and low sensitivity. ACTA CRYSTALLOGRAPHICA SECTION B, STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS 2022; 78:133-139. [PMID: 35411852 DOI: 10.1107/s2052520622000245] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 01/06/2022] [Indexed: 06/14/2023]
Abstract
A cocrystal explosive comprising 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) and 1-methyl-2,4,5-trinitroimidazole (MTNI) (molar ratio, 1:1) was synthesized. The structure of the cocrystal was characterized by single-crystal X-ray diffraction. Its structure was further determined by powder X-ray diffraction, infrared spectroscopy and differential scanning calorimetry which showed that its morphology was different from the morphology of the mechanical mixture of two raw materials. The decomposition temperature of the cocrystal is lower than that of CL-20 and MTNI. The calculated detonation performance is slightly lower than that of HMX, but the cocrystal has excellent sensitivity performance relative to that of CL-20, even lower than that of RDX. These features make this cocrystal ideal to be used in applications with low-sensitivity requirements.
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Key Words
- 1-methyl-2,4,5-trinitroimidazole
- 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane
- cocrystal
- differential scanning calorimetry
- single crystal X-ray diffraction
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Affiliation(s)
- Pengbao Lian
- School of Chemical Engineering and Technology, North University of China, College Road 3, Taiyuan, Shanxi 030051, People's Republic of China
| | - Luyao Zhang
- Scientific Research and Technology Development Department, Gansu Yin'guang Chemical Industry Group, Baiyin, Gansu 730900, People's Republic of China
| | - Hongping Su
- Scientific Research and Technology Development Department, Gansu Yin'guang Chemical Industry Group, Baiyin, Gansu 730900, People's Republic of China
| | - Jun Chen
- Hubei Dongfang Chemical Industry Co., Ltd, Xiangyang, Hubei 441403, People's Republic of China
| | - Lizhen Chen
- School of Chemical Engineering and Technology, North University of China, College Road 3, Taiyuan, Shanxi 030051, People's Republic of China
| | - Jianlong Wang
- School of Chemical Engineering and Technology, North University of China, College Road 3, Taiyuan, Shanxi 030051, People's Republic of China
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Patil VB, Yan QL, Trzciński WA, Bělina P, Shánělová J, Musil T, Zeman S. Co-agglomerated crystals of cyclic nitramines with sterically crowded molecules. CrystEngComm 2022. [DOI: 10.1039/d2ce00840h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Co-crystallization of cyclic nitramines with sterically crowded molecules, i.e., ε-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (ε-CL-20) with cis-1,3,4,6-tetranitrooctahydroimidazo-[4,5-d]imidazole, is difficult, but co-agglomeration given good results.
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Affiliation(s)
- Veerabhadragouda B. Patil
- Institute of Energetic Materials, Faculty of Chemical Technology, University of Pardubice, CZ-532 10 Pardubice, Czech Republic
| | - Qi-Long Yan
- School of Astronautics, Northwestern Polytechnical University, Xi'an 710 072, Shaanxi, China
| | - Waldemar A. Trzciński
- Faculty of Advanced Technology and Chemistry, Military University of Technology, PL-00 908 Warsaw, Poland
| | - Petr Bělina
- Department of Inorganic Technology, Faculty of Chemical Technology, University of Pardubice, CZ-532 10 Pardubice, Czech Republic
| | - Jana Shánělová
- Department of Physical Chemistry, Faculty of Chemical Technology, University of Pardubice, CZ-532 10 Pardubice, Czech Republic
| | - Tomáš Musil
- Austin Detonator, Inc., CZ-755 01 Vsetín, Czech Republic
| | - Svatopluk Zeman
- Institute of Energetic Materials, Faculty of Chemical Technology, University of Pardubice, CZ-532 10 Pardubice, Czech Republic
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7
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Eid A, Rahman MA, Al-Abadleh HA. Mechanistic studies on the conversion of NO gas on urea-iron and copper metal organic frameworks at low temperature conditions: in situ infrared spectroscopy and Monte Carlo investigations. CAN J CHEM 2021. [DOI: 10.1139/cjc-2021-0130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nitrogen oxide (NOx) emissions from high-temperature combustion processes under fuel-lean conditions continue to be a challenge for the energy industry. Selective catalytic reduction (SCR) is possible using metal oxides and zeolites. There is still a need to identify catalytic materials that are efficient in reducing NOx to environmentally benign nitrogen gas at temperatures lower than 200 °C. Metal-organic frameworks (MOFs) have emerged as a class of highly porous materials with unique physical and chemical properties. This study is motivated by the lack of systematic investigations on SCR using MOFs under industrially relevant conditions. Here, we investigate the extent of NO conversion with two commercially available MOFs, Basolite F300 (Fe-BTC) and HKUST-1 (Cu-BTC), mixed with solid urea as a source for the reductant, ammonia gas. For comparison, experiments were also conducted using cobalt ferrite (CoFe2O4) as a non-porous counterpart to relate its reactivity to those obtained from MOFs. Fourier-transform infrared spectroscopy (FTIR) was utilized to identify the gas and surface species in the temperature range of 115–180 °C. Computational analysis was performed using Monte Carlo simulations to quantify the adsorption energies of different surface species. The results show that the rate of ammonia production from the in situ solid urea decomposition was higher using CoFe2O4 than Fe-BTC and Cu-BTC and that there was very limited conversion of NO on the mixed solid urea-MOF systems due to site blocking. The main conclusions from this study are that MOFs have limited ability to convert NO under low-temperature conditions and that surface regeneration requires additional experimental steps.
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Affiliation(s)
- A.M. Eid
- Department of Chemistry and Biochemistry, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada
- Department of Chemistry and Biochemistry, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada
| | - Mohammad A. Rahman
- Department of Chemistry and Biochemistry, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada
- Department of Chemistry and Biochemistry, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada
| | - Hind A. Al-Abadleh
- Department of Chemistry and Biochemistry, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada
- Department of Chemistry and Biochemistry, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada
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Chen L, Cao X, Chen Y, Li Q, Wang Y, Wang X, Qin Y, Cao X, Liu J, Shao Z, He W. Biomimetic-Inspired One-Step Strategy for Improvement of Interfacial Interactions in Cellulose Nanofibers by Modification of the Surface of Nitramine Explosives. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:8486-8497. [PMID: 34236199 DOI: 10.1021/acs.langmuir.1c00874] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Recently, a burgeoning category of biocompatible botanically derived nanomaterial cellulose nanofibers (CNFs) has captured tremendous attention on account of its entangled nanostructured network, natural abundance, and outstanding mechanical properties. Biomimetically inspired by the superior properties of CNFs, this paper examined them as the coating material to cover cyclotrimethylenetrinitramine (RDX), cyclotetramethylenetetranitramine (HMX), and hexanitrohexaazaisowurtzitane (CL-20) via a facile water suspension method and the ultrasonic technology. The core-shell structure and the composition of energetic crystal@CNF were examined through scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy analyses. The obtained outcomes demonstrated that the dispersibility of the CNF enhanced favorably upon covering the surface of explosive crystals; the interfacial contact ability between CNFs and energetic crystals was also manifested to be increased, which could be ascribed to the interfacial interaction of hydrogen bonds and the electrostatic force of self-assembly. In addition, the stable crystalloid construction of β-HMX and ε-CL-20 has been preserved positively in the preparation process. In comparison with raw explosives, the thermal stability and sensitivity performances of the core-shell structure composites were outstanding. Accordingly, this work demonstrated the rewarding application of coating CNFs uniformly on the surface of energetic crystals, ulteriorly offering a potential fabrication strategy for the embellishment of high-explosive crystals.
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Affiliation(s)
- Ling Chen
- Key Laboratory of Special Energy Materials Ministry of Education, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Xinfu Cao
- Inner Mongolia Synthetic Chemical and Engineering Institute, Hohhot 010010, China
| | - Yong Chen
- Institute of Chemical Defence, Academy of Military Sciences, Zhijiang, Hubei 443200, China
| | - Qiang Li
- Key Laboratory of Special Energy Materials Ministry of Education, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Yingbo Wang
- Key Laboratory of Special Energy Materials Ministry of Education, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Xijin Wang
- Key Laboratory of Special Energy Materials Ministry of Education, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Yang Qin
- National Special Superfine Powder Engineering Research Center of China, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Xiang Cao
- Key Laboratory of Special Energy Materials Ministry of Education, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Jie Liu
- National Special Superfine Powder Engineering Research Center of China, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Ziqiang Shao
- School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Weidong He
- Key Laboratory of Special Energy Materials Ministry of Education, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
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9
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Hu Y, Yuan S, Li X, Liu M, Sun F, Yang Y, Hao G, Jiang W. Preparation and Characterization of Nano-CL-20/TNT Cocrystal Explosives by Mechanical Ball-Milling Method. ACS OMEGA 2020; 5:17761-17766. [PMID: 32724868 PMCID: PMC7379102 DOI: 10.1021/acsomega.0c02426] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 06/23/2020] [Indexed: 06/11/2023]
Abstract
Nano-CL-20/TNT cocrystal explosive was successfully prepared by mechanical ball milling with 0.38 mm grinding beads. The micromorphology and particle size of cocrystal explosive were characterized by scanning electron microscopy. The average particle size of nano-CL-20/TNT cocrystal explosive was 119.5 nm and showed a spherical-like micromorphology. The crystal structure of cocrystal explosive was characterized by powder X-ray diffraction, infrared spectroscopy, and Raman spectroscopy. The results show that mechanical ball milling does not change the molecular structure of the raw material, but the sample after ball milling has a new crystal phase, rather than a simple mixing of raw materials. Differential scanning calorimetry tests show that nano-CL-20/TNT cocrystal explosive has a higher decomposition temperature; impact sensitivity tests show that the properties of cocrystal explosive are 26 and 21.7 cm higher than those of CL-20 and CL-20/TNT mixture, respectively, which indicates that nano-CL-20/TNT cocrystal explosive has better thermal stability and safety.
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Affiliation(s)
- Yubing Hu
- National
Special Superfine Powder Engineering Research Center of China, School
of Chemical Engineering, Nanjing University
of Science and Technology, Nanjing 210094, P. R. China
| | - Shuo Yuan
- National
Special Superfine Powder Engineering Research Center of China, School
of Chemical Engineering, Nanjing University
of Science and Technology, Nanjing 210094, P. R. China
| | - Xiaojiang Li
- Science
and Technology on Combustion and Explosion Laboratory, Xi’an Modern Chemistry Research Institute, Xi’an 710065, P. R. China
| | - Meng Liu
- Science
and Technology on Combustion and Explosion Laboratory, Xi’an Modern Chemistry Research Institute, Xi’an 710065, P. R. China
| | - Fengxi Sun
- Gansu
Yinguang Chemical Industry Group Co., Ltd., Baiyin 730900, P. R. China
| | - Yanpeng Yang
- Gansu
Yinguang Chemical Industry Group Co., Ltd., Baiyin 730900, P. R. China
| | - Gazi Hao
- National
Special Superfine Powder Engineering Research Center of China, School
of Chemical Engineering, Nanjing University
of Science and Technology, Nanjing 210094, P. R. China
| | - Wei Jiang
- National
Special Superfine Powder Engineering Research Center of China, School
of Chemical Engineering, Nanjing University
of Science and Technology, Nanjing 210094, P. R. China
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10
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Comparative investigation on the thermostability, sensitivity, and mechanical performance of RDX/HMX energetic cocrystal and its mixture. J Mol Model 2020; 26:176. [PMID: 32535754 DOI: 10.1007/s00894-020-04426-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 05/18/2020] [Indexed: 11/27/2022]
Abstract
Molecular mechanics (MM) and molecular dynamics (MD) simulation method were applied to explore the impact of temperature (220-380 K) on the thermostability, sensitivity, and mechanical performance of RDX (1,3,5-trinitro-1,3,5-triazacyco-hexane)/HMX (1,3,5,7-tetranitro-1,3,5,7-tetrazocane) energetic cocrystal and mixture models. The mechanical property, the maximum trigger bond length ([Formula: see text]), binding energy, and cohesive energy density (CED) of the pure RDX, β-HMX crystal, the cocrystal, and mixture models were acquired and compared. The results manifest that temperature has an important impact on the binding capacity between the components of the cocrystal and mixture. The binding energies decrease as the temperature rises, and the cocrystal has larger values than those of mixture. For all the models, the [Formula: see text] increases and the CEDs decrease with the rising temperature, implying that the sensitivity of the explosives increases, while the [Formula: see text] values of the cocrystal are smaller than those of HMX and the CED values are between those of RDX and β-HMX, indicating that the sensitivity has been enhanced through co-crystallization. As the temperature increases, the shear modulus (G), bulk modulus (K), and tensile modulus (E) values of all models have an evident downtrend. Simultaneously, G, K, and E values of the cocrystal model are less than those of RDX and β-HMX, while the K/G ratio and Cauchy pressure (C12-C44) are larger, signifying that co-crystallization can weaken the brittleness and enhance the ductility of the pure crystals. Compared with the mixture, the cocrystal has better ductility and stability.
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Key Words
- 1,3,5-trinitro-1,3,5-triazacyco-hexane (RDX)/1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) energetic cocrystal
- Mechanical performance
- Molecular dynamics simulation
- Sensitivity
- Thermostability
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11
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Study on phonon spectra and heat capacities of CL-20/MTNP cocrystal and co-formers by density functional theory method. J Mol Model 2020; 26:148. [PMID: 32440794 DOI: 10.1007/s00894-020-04415-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 05/09/2020] [Indexed: 10/24/2022]
Abstract
The phonon spectra and heat capacities of 2, 4, 6, 8, 10, 12-hexanitrohexaazaisowurtzitane/1-methyl-3, 4, 5-trinitropyrazole (CL-20/MTNP) cocrystal and co-formers were calculated in the framework of DFT. By analyzing the phonon density of states (DOS), the energy flow directions and trigger bonds of cocrystal and co-formers have been obtained and the microscopic physical nature was revealed for thermal decomposition mechanism, detonation performance, and sensitivity. For CL-20/MTNP cocrystal, the phonon number of "doorway" modes and the characteristic vibrational frequencies Δωd are between those of its co-formers, which can provide the microscopic understanding for the ordering of impact sensitivity at experiment, ε-CL-20 > CL-20/MTNP > MTNP. In CL-20/MTNP cocrystal, more phonons and stronger phonon DOS peaks of CL-20 molecules than those of MTNP molecules mean cocrystal's detonation performance is mainly dominated by CL-20 molecules. The heat capacities obtained by the Debye model rise with elevated temperatures at 0-600 K and the order is ε-CL-20 > CL-20/MTNP > MTNP. Graphical abstract The phonon spectra and heat capacities of CL-20/MTNP cocrystal and co-formers were calculated by density functional theory (DFT). In CL-20/MTNP cocrystal, the detonation performance and impact sensitivity are mainly dominated by CL-20 molecules. The broken bonds caused by energy transfer may undergo a multi-phonon pumping process.
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Theoretical calculation into the structures, stability, sensitivity, and mechanical properties of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12 hexaazai-sowurtzitane (CL-20)/1-amino-3-methyl-1,2,3-triazoliumnitrate (1-AMTN) cocrystal and its mixture. Struct Chem 2019. [DOI: 10.1007/s11224-019-01447-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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13
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Theoretical calculation into the effect of molar ratio on the structures, stability, mechanical properties and detonation performance of 1,3,5,7-tetranitro-1,3,5,7-tetrazocane/ 1,3,5-trinitro-1,3,5-triazacyco-hexane cocrystal. J Mol Model 2019; 25:299. [PMID: 31482441 DOI: 10.1007/s00894-019-4181-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 08/20/2019] [Indexed: 10/26/2022]
Abstract
Molecular dynamics (MD) simulation was conducted to research the effect of molar ratio on the thermal stability, mechanical properties, and detonation performance of HMX (1,3,5,7-tetranitro-1,3,5,7-tetrazocane)/RDX (1,3,5-trinitro-1,3,5-triazacyco-hexane) cocrystal explosive at ambient condition. The binding energy, mechanical properties, and the detonation parameters of the pure β-HMX, RDX crystal, and the cocrystal models were got and contrasted. The results demonstrate that molar ratio has a great influence on the properties of the cocrystal system. The binding energy of the cocrystals has the maximum values at the 1:1 molar ratio, indicating that the stability of HMX/RDX(1:1) cocrystal is the best and HMX and RDX may prefer to cocrystallizing at 1:1 molar ratio. What's more, the tensile modulus (E) and shear modulus (G) of the HMX/RDX(1:1) cocrystals have the minimum value, while the C12-C44 and K/G have the maximum value, implying that the cocrystal at 1:1 molar ratio has the best mechanical properties. Simultaneously, the E, K, and G of the cocrystals are all smaller than those of β-HMX's and generally larger than those RDX's, while the Cauchy pressure (C12-C44) and K/G ratio were greater, demonstrating that cocrystallizing can improve the brittleness and enhance the ductility. The detonation velocity (D) and detonation pressure (P) decrease with the rising RDX content, while the properties are still superior to the pure RDX crystal; thus, the energy properties of the cocrystal are still excellent. In a word, HMX/RDX cocrystal at 1:1 molar ratio has the best thermal stability, mechanical properties, and the excellent energetic performance.
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