物理化学学报2020，Vol.36Issue(6)：71-77,7.DOI:10.3866/PKU.WHXB201905085
三维无溶剂含能Ag-MOF的制备、热分解动力学及爆炸性能
Synthesis, Thermal Decomposition Kinetics and Detonation Performance of a Three-Dimensional Solvent-Free Energetic Ag(Ⅰ)-MOF
摘要
Abstract
Solvent molecules can significantly reduce the heat of detonation and stability of energetic metal-organic framework (EMOF) materials,and the development of solvent-free EMOFs has become an effective strategy to prepare high-energy density materials.In this study,a solvent-free EMOF,[Agz(DTPZ)]n (1) (N％ =32.58％),was synthesized by reacting a high-energy ligand,2,3-di(1H-tetrazol-5-yl)pyrazine (H2DTPZ),with silver ions under hydrothermal conditions,and it was structurally characterized by elemental analysis,infrared spectroscopy,X-ray diffraction,and thermal analysis.In 1,the DTPZ2-ligands that adopted a highly torsional configuration bridged the Ag+ ions in an octadentate coordination mode to form a three-dimensional framework (ρ =2.812 g·cm-3).The large steric effect and strong coordination ability of DTPZ2-effectively prevented the solvent molecules from binding with the metal centers or occupying the voids of 1.Moreover,the strong π-π stacking interactions[centroid-centroid distance =0.34461(1) nm]between the tetrazole rings in different DTPZ2-ligands provided a high thermal stability to the framework (T6 =619.1 K,Tp =658.7 K).Thermal analysis showed that a one-step rapid weight loss with intense heat release primarily occurred during the decomposition of 1,suggesting potential energetic characteristics.Non-isothermal thermokinetic analyses (based on the Kissinger and Ozawa-Doyle methods) were performed using differential scanning calorimetry to obtain the thermoanalysis kinetic parameters of the thermodecomposition of 1 (Ea =272.1 kJ·mol-1,E0 =268.9 kJ·mol-1;IgA =19.67 s-1).The related thermodynamic parameters[enthalpy of activation (△H≠ 266.9 kJ·mol-1),entropy of activation (△S≠ 125.4 J·mol-1·K-1),free energy of activation (△G≠ 188.3 kJ·mol-1)],critical temperature of thermal explosion (Tb =607.1 K),and self-accelerating decomposition temperature (TSADT =595.8 K) of the decomposition reaction were also calculated based on the decomposition peak temperature and extrapolated onset temperature when the heating rate approached zero.The results revealed that 1 featured good thermal safety,and its decomposition was a non-spontaneous entropy-driven process.The standard molar enthalpy for the formation of 1 was calculated to be (2165.99 + 0.81) kJ· mol-1 based on its constant volume combustion energy determined using a precise rotating oxygen bomb calorimeter.Detonation and safety performance tests revealed that 1 was insensitive to impact and friction,and its heat of detonation (10.15 kJ·g-1) was higher than that of common ammonium nitrate explosives,such as octogen (HMX),hexogene (RDX),and 2,4,6-trinitrotoluene (TNT),indicating that 1 is a promising high-energy and insensitive material.关键词
含能金属-有机框架/热分解动力学/热稳定性/爆炸性能/感度Key words
Energetic metal-organic framework/Thermal decomposition kinetics/Thermal stability/Detonation performance/Sensitivity分类
化学化工引用本文复制引用
乔成芳,吕磊,许文风,夏正强,周春生,陈三平,高胜利..三维无溶剂含能Ag-MOF的制备、热分解动力学及爆炸性能[J].物理化学学报,2020,36(6):71-77,7.基金项目
The project was supported by the National Natural Science Foundation of China (21727805,21673180,21703135,21803042),Natural Science Basic Research Program of Shaanxi (2017JZ002,2018JM5180,2019JQ-249,2019JQ-067),the Project of Shaanxi Key Laboratory of Chemical Reaction Engineering (14JS112) and the 64th China Postdoctoral Science Foundation Funded Project (2018M643706).国家自然科学基金(21727805,21673180,21703135,21803042),陕西省自然科学基础研究计划(2017JZ002,2018JM5180,2019JQ-249,2019JQ-067),陕西省化学反应工程重点实验室项目(14JS112)和第64批中国博士后科学基金面上项目(2018M643706)资助项目 （21727805,21673180,21703135,21803042）
