High energy density with low mechanical sensitivity: A novel energetic cocrystal composed of CL-20 and FOX-7 obtained by electrostatic spray method

IF 4 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Structure Pub Date : 2025-03-23 DOI:10.1016/j.molstruc.2025.142138

Guiyun Hang, Jintao Wang, Tao Wang, Haijian Xue, Huiming Shen, Wenli Yu

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引用次数: 0

Abstract

Cocrystallization technique is an effective strategy to tune performances of materials and it has been proved to be a novel and promising approach to decrease mechanical sensitivity and improve physicochemical properties of energetic compounds. In this work, based on the high energy density compound 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12- hexaazaisowurtzitane (CL-20) and insensitive energetic compound 1,1-diamino-2,2-dinitroethylene (FOX-7), a novel CL-20/FOX-7 cocrystal (molar ratio 1:1) was prepared by electrostatic spray method and the crystal structure, thermal behavior, mechanical sensitivity and energetic property were characterized and the intermolecular interaction was analyzed. Scanning electron microscopy (SEM) reveals that the cocrystal has smooth crystal surface, the particle size is within 1 μm∼5 μm, and the crystal morphology is different from CL-20 and FOX-7. Powder X-ray diffraction (PXRD) indicates that a new substance is formed between CL-20 and FOX-7. Fourier transform infrared spectroscopy (FT-IR) illustrates that the absorption peaks in cocrystal is shifted from 5 cm⁻¹ to 10 cm⁻¹, meaning that intermolecular interaction is formed. Differential scanning calorimetry (DSC) results declares that the melting point of cocrystal is 7.5 °C higher than FOX-7, while the thermal decomposition temperature is decreased by 7.0 °C. The mechanical sensitivity indicates that compared with raw CL-20, the impact sensitivity of CL-20/FOX-7 cocrystal is decreased by 64 %, drop height is increased by 31 cm and friction sensitivity is decreased by 68 %. The predicted crystal density, and detonation parameters of CL-20/FOX-7 energetic cocrystal are 1.928 g/cm³, 9178 m/s, 40.44 GPa, these parameters are higher than HMX, implying that this cocrystal has high energy density. The intermolecular interactions in CL-20/FOX-7 cocrystal mainly include hydrogen bonding and van der Waals (vdW) forces. Therefore, the CL-20/FOX-7 cocrystal is a novel energetic material with high energy density and low mechanical sensitivity, and it has wide application prospect in the near future.

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来源期刊

Journal of Molecular Structure 化学-物理化学

CiteScore

7.10

自引率

15.80%

发文量

2384

审稿时长

45 days

期刊介绍： The Journal of Molecular Structure is dedicated to the publication of full-length articles and review papers, providing important new structural information on all types of chemical species including: • Stable and unstable molecules in all types of environments (vapour, molecular beam, liquid, solution, liquid crystal, solid state, matrix-isolated, surface-absorbed etc.) • Chemical intermediates • Molecules in excited states • Biological molecules • Polymers. The methods used may include any combination of spectroscopic and non-spectroscopic techniques, for example: • Infrared spectroscopy (mid, far, near) • Raman spectroscopy and non-linear Raman methods (CARS, etc.) • Electronic absorption spectroscopy • Optical rotatory dispersion and circular dichroism • Fluorescence and phosphorescence techniques • Electron spectroscopies (PES, XPS), EXAFS, etc. • Microwave spectroscopy • Electron diffraction • NMR and ESR spectroscopies • Mössbauer spectroscopy • X-ray crystallography • Charge Density Analyses • Computational Studies (supplementing experimental methods) We encourage publications combining theoretical and experimental approaches. The structural insights gained by the studies should be correlated with the properties, activity and/ or reactivity of the molecule under investigation and the relevance of this molecule and its implications should be discussed.