Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ ...Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA chips.The aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition ability.In this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through spectrophotometry.The spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test results.The optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content test.Compared with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory accuracy.Moreover,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was studied.This study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems.展开更多
In the pursuit of advancing imidazolium-based energetic ionic liquids (EILs),the current study is devoted to the synthesis and characterization of 1,3-dibutyl-imidazolium azide ([BBIm][N_(3)]),as a novel member in thi...In the pursuit of advancing imidazolium-based energetic ionic liquids (EILs),the current study is devoted to the synthesis and characterization of 1,3-dibutyl-imidazolium azide ([BBIm][N_(3)]),as a novel member in this ionic liquids class.The chemical structure of this EIL was rigorously characterized and confirmed using FTIR spectroscopy,1D,and 2D-NMR analyses.The thermal behavior assessment was conducted through DSC and TGA experiments.DSC analysis revealed an endothermic glass transition at T_(g)=-61℃,followed by an exothermic degradation event at T_(onset)=311℃.Similarly,TGA thermograms exhibited a one-stage decomposition process resulting in 100% mass loss of the sample.Furthermore,the short-term thermal stability of the azide EIL was investigated by combining the non-isothermal TGA data with the TAS,it-KAS,and VYA/CE isoconversional kinetic approaches.Consequently,the Arrhenius parameters(E_(a)=154 kJ·mol^(-1),Log(A/s^(-1))=11.8) and the most probable reaction model g(a) were determined.The observed high decomposition temperatures and the significantly elevated activation energy affirm the enhanced thermal stability of the modified EIL.These findings revealed that[BBIm][N_(3)]EIL can be a promising candidate for advanced energetic material application.展开更多
Copper azide(CA), as a primary explosive with high energy density, has not been practically used so far because of its high electrostatic sensitivity. The Cu2O@HKUST-1 core-shell structure hybrid material was synthesi...Copper azide(CA), as a primary explosive with high energy density, has not been practically used so far because of its high electrostatic sensitivity. The Cu2O@HKUST-1 core-shell structure hybrid material was synthesized by the “bottle around ship” methodology in this research by regulating the dissolution rate of Cu2O and the generation rate of metal-organic framework(MOF) materials. Cu2O@HKUST-1 was carbonized to form a Cu O@porous carbon(CuO@PC) composite material. CuO@PC was synthesized into a copper azide(CA) @PC composite energetic material through a gas-solid phase in-situ azidation reaction.CA is encapsulated in PC framework, which acts as a nanoscale Faraday cage, and its excellent electrical conductivity prevents electrostatic charges from accumulating on the energetic material’s surface. The CA@PC composite energetic material has a CA content of 89.6%, and its electrostatic safety is nearly 30times that of pure CA(1.47 mJ compared to 0.05 mJ). CA@PC delivers an outstanding balance of safety and energy density compared to similar materials.展开更多
Copper azide with high density was successfully synthesized by in-situ reaction of nanoporous copper(NPC)precursor with HN_(3) gaseous.NPC with pore size of about 529 nm has been prepared by electroless plating using ...Copper azide with high density was successfully synthesized by in-situ reaction of nanoporous copper(NPC)precursor with HN_(3) gaseous.NPC with pore size of about 529 nm has been prepared by electroless plating using polystyrene(PS)as templates.The copper shells thickness of NPC was controlled by adjusting the PS loading amount.The effects of copper shell on the morphology,structure and density of copper azide were investigated.The conversion increased from 87.12%to 95.31%when copper shell thickness decrease from 100 to 50 nm.Meanwhile,the density of copper azide prepared by 529 nm NPC for 24 h was up to 2.38 g/cm^(3).The hollow structure of this NPC was filled by swelling of copper azide which guaranteed enough filling volume for keeping the same shape as well as improving the charge density.Moreover,HNS-IV explosive was successfully initiated by copper azide with minimum charge thickness of 0.55 mm,showing that copper azide prepared has excellent initiation performance,which has more advantages in the application of miniaturized explosive systems.展开更多
Due to its extremely low electrostatic sensitivity,copper azide primary explosive is greatly limited in practical applications.In this study,a composite film with Cu-MOF in-situ growth on carbon nanofilm was prepared ...Due to its extremely low electrostatic sensitivity,copper azide primary explosive is greatly limited in practical applications.In this study,a composite film with Cu-MOF in-situ growth on carbon nanofilm was prepared by electrospinning and solvothermal methods,and CNF@Cu-N3film with electrostatic safety was obtained by carbonization and azide later.Its electrostatic sensitivity(E50)was greatly increased from 0.05 mJ of raw materials to 4.06 mJ,and still maintained a good detonation performance which could successfully detonate the CL-20 secondary explosive.This is mainly due to the synergistic effect of the carbon film and the MOF structure,which greatly improves the conductivity of the entire system and the uniform distribution of copper particles,providing a new preparation strategy for metal azide film that is suitable for the micro-initiator device.展开更多
Aluminum(Al) particles are good fuel additives to improve the energy output performances of explosives. Under detonation environment, reaction delay of Al particles plays a key role in the energy release efficiency. U...Aluminum(Al) particles are good fuel additives to improve the energy output performances of explosives. Under detonation environment, reaction delay of Al particles plays a key role in the energy release efficiency. Up to date, reaction delay of Al particles is still limited by the efficiency of mass and heat transfer from oxidizers to Al particles. To address this issue, a homogeneous fuel-oxidizer assembly has recently become a promising strategy. In this work, oxidizer-activated Al fuel particles(ALG) were prepared with glycidyl azide polymer(GAP) as the oxidizer. The ALG was in uniform spherical shape and core-shell structure with shell layer of around 5 nm which was observed by scanning electron microscope and transmission electron microscope. The localized nanoscale mid-IR measurement detected the uniform distribution of characteristic absorption bond of GAP in the shell layer which confirmed the homogenous fuel-oxidizer structure of ALG. A thermal gravimetric analysis of ALG at ultrafast heating rate of 1000℃/min under argon atmosphere was conducted. The decomposition of GAP finished much earlier than that of GAP at heating rate of 10℃/min. Under ultrafast high laser fluence, the reaction response of ALG was characterized and compared with that of micro-sized Al(μAl). With the increase of laser energy, the propagation distance of the shock wave increased. However, the velocity histories were nearly the same when energies were lower than 299 mJ or higher than 706 mJ. The propagation distance of the shock wave for ALG was 0.5 mm larger than that for μAl at 2.1 μs. The underwater explosion showed the peak pressure and the shock wave energy of the ALG-based explosive were both higher than those of the μAl-based explosive at 2.5 m. This study shows the feasibility to improve the energy release of Al-based explosives via using the oxidizer-activated Al fuel particles with energetic polymer as the oxidizer.展开更多
Progress in the rocket industry is only possible on the basis of new, higher performance and more environmentally friendly materials compared to up-to-date propellant ingredients for liquid, solid, gelled and hybrid p...Progress in the rocket industry is only possible on the basis of new, higher performance and more environmentally friendly materials compared to up-to-date propellant ingredients for liquid, solid, gelled and hybrid propellant systems. In this work, synthetic methods have been developed for the preparation of new energetic azofurazans bearing nitroxymethyl or azidomethyl groups. All prepared compounds were fully characterized by multinuclear NMR and IR spectroscopies, as well as elemental analyses. An analysis of the structural features based on the X-ray single-crystal diffraction made it possible to discuss their influence on the densities of the azofurazans of this study. Thermal decomposition and combustion of nitroxymethyl and azidomethyl azofurazans were studied using a number of complementary experimental techniques, namely thermogravimetry, differential scanning calorimetry, manometry, microthermocouple measurements in the combustion wave. The structural and physical characteristics of these new energetic analogues illustrate the extent to which the nature of the explosophoric groups can be used to tune the performace of the azofurazan framework. These azofurazans possess positive calculated enthalpy of formation and are promising candidates for new environmentally friendly energetic materials.展开更多
Different GAP-based CSRP samples with different binder contents were prepared and compared with that of conventional HTPB propellant.The crosslinker mixture of trimethylol propane(TMP)and butane diol(BD)was used in th...Different GAP-based CSRP samples with different binder contents were prepared and compared with that of conventional HTPB propellant.The crosslinker mixture of trimethylol propane(TMP)and butane diol(BD)was used in the GAP matrix beside the addition of dibutyltin dilaurate(DBTDL)to ensure cross-linking and curing completion of the prepared CSRP.The viscosity and hardness of all prepared formulations were monitored continuously during the curing process.The mechanical characteristics of cured samples were tested.The burning rate at operating pressure and specific impulse were measured,while the theoretical specific impulse(I sp)was calculated by ICT code and compared with the measured results.According to the results,DOA was found to be a suitable plasticizer for GAP when using in propellant.The mechanical properties of CSRP with 25%GAP can produce the optimum mechanical behavior,which is close to that of HTPB-based CSRP.The optimum GAP-based formulation is one candidate to replace the traditional HTPB-based CSRP with high burning rate for some applications.展开更多
基金the financial support provided by the National Natural Science Foundation of China(Grant No.11872013).
文摘Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA chips.The aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition ability.In this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through spectrophotometry.The spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test results.The optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content test.Compared with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory accuracy.Moreover,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was studied.This study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems.
文摘In the pursuit of advancing imidazolium-based energetic ionic liquids (EILs),the current study is devoted to the synthesis and characterization of 1,3-dibutyl-imidazolium azide ([BBIm][N_(3)]),as a novel member in this ionic liquids class.The chemical structure of this EIL was rigorously characterized and confirmed using FTIR spectroscopy,1D,and 2D-NMR analyses.The thermal behavior assessment was conducted through DSC and TGA experiments.DSC analysis revealed an endothermic glass transition at T_(g)=-61℃,followed by an exothermic degradation event at T_(onset)=311℃.Similarly,TGA thermograms exhibited a one-stage decomposition process resulting in 100% mass loss of the sample.Furthermore,the short-term thermal stability of the azide EIL was investigated by combining the non-isothermal TGA data with the TAS,it-KAS,and VYA/CE isoconversional kinetic approaches.Consequently,the Arrhenius parameters(E_(a)=154 kJ·mol^(-1),Log(A/s^(-1))=11.8) and the most probable reaction model g(a) were determined.The observed high decomposition temperatures and the significantly elevated activation energy affirm the enhanced thermal stability of the modified EIL.These findings revealed that[BBIm][N_(3)]EIL can be a promising candidate for advanced energetic material application.
基金the financial support by Postgraduate Research & Practice Innovation Program from Jiangsu Science and Technology Department under Grant number KYCX19_0320。
文摘Copper azide(CA), as a primary explosive with high energy density, has not been practically used so far because of its high electrostatic sensitivity. The Cu2O@HKUST-1 core-shell structure hybrid material was synthesized by the “bottle around ship” methodology in this research by regulating the dissolution rate of Cu2O and the generation rate of metal-organic framework(MOF) materials. Cu2O@HKUST-1 was carbonized to form a Cu O@porous carbon(CuO@PC) composite material. CuO@PC was synthesized into a copper azide(CA) @PC composite energetic material through a gas-solid phase in-situ azidation reaction.CA is encapsulated in PC framework, which acts as a nanoscale Faraday cage, and its excellent electrical conductivity prevents electrostatic charges from accumulating on the energetic material’s surface. The CA@PC composite energetic material has a CA content of 89.6%, and its electrostatic safety is nearly 30times that of pure CA(1.47 mJ compared to 0.05 mJ). CA@PC delivers an outstanding balance of safety and energy density compared to similar materials.
基金the financial support provided by the National Natural Science Foundation of China(No.11872013)。
文摘Copper azide with high density was successfully synthesized by in-situ reaction of nanoporous copper(NPC)precursor with HN_(3) gaseous.NPC with pore size of about 529 nm has been prepared by electroless plating using polystyrene(PS)as templates.The copper shells thickness of NPC was controlled by adjusting the PS loading amount.The effects of copper shell on the morphology,structure and density of copper azide were investigated.The conversion increased from 87.12%to 95.31%when copper shell thickness decrease from 100 to 50 nm.Meanwhile,the density of copper azide prepared by 529 nm NPC for 24 h was up to 2.38 g/cm^(3).The hollow structure of this NPC was filled by swelling of copper azide which guaranteed enough filling volume for keeping the same shape as well as improving the charge density.Moreover,HNS-IV explosive was successfully initiated by copper azide with minimum charge thickness of 0.55 mm,showing that copper azide prepared has excellent initiation performance,which has more advantages in the application of miniaturized explosive systems.
基金financial support from the National Natural Science Foundation of China(Grant No.12102051)the State Key Laboratory of Explosion Science and Technology(Grant No.QNKT2022-04)。
文摘Due to its extremely low electrostatic sensitivity,copper azide primary explosive is greatly limited in practical applications.In this study,a composite film with Cu-MOF in-situ growth on carbon nanofilm was prepared by electrospinning and solvothermal methods,and CNF@Cu-N3film with electrostatic safety was obtained by carbonization and azide later.Its electrostatic sensitivity(E50)was greatly increased from 0.05 mJ of raw materials to 4.06 mJ,and still maintained a good detonation performance which could successfully detonate the CL-20 secondary explosive.This is mainly due to the synergistic effect of the carbon film and the MOF structure,which greatly improves the conductivity of the entire system and the uniform distribution of copper particles,providing a new preparation strategy for metal azide film that is suitable for the micro-initiator device.
基金National Natural Science Foundation of China(Grant No.11832006,U1530262,21975024).
文摘Aluminum(Al) particles are good fuel additives to improve the energy output performances of explosives. Under detonation environment, reaction delay of Al particles plays a key role in the energy release efficiency. Up to date, reaction delay of Al particles is still limited by the efficiency of mass and heat transfer from oxidizers to Al particles. To address this issue, a homogeneous fuel-oxidizer assembly has recently become a promising strategy. In this work, oxidizer-activated Al fuel particles(ALG) were prepared with glycidyl azide polymer(GAP) as the oxidizer. The ALG was in uniform spherical shape and core-shell structure with shell layer of around 5 nm which was observed by scanning electron microscope and transmission electron microscope. The localized nanoscale mid-IR measurement detected the uniform distribution of characteristic absorption bond of GAP in the shell layer which confirmed the homogenous fuel-oxidizer structure of ALG. A thermal gravimetric analysis of ALG at ultrafast heating rate of 1000℃/min under argon atmosphere was conducted. The decomposition of GAP finished much earlier than that of GAP at heating rate of 10℃/min. Under ultrafast high laser fluence, the reaction response of ALG was characterized and compared with that of micro-sized Al(μAl). With the increase of laser energy, the propagation distance of the shock wave increased. However, the velocity histories were nearly the same when energies were lower than 299 mJ or higher than 706 mJ. The propagation distance of the shock wave for ALG was 0.5 mm larger than that for μAl at 2.1 μs. The underwater explosion showed the peak pressure and the shock wave energy of the ALG-based explosive were both higher than those of the μAl-based explosive at 2.5 m. This study shows the feasibility to improve the energy release of Al-based explosives via using the oxidizer-activated Al fuel particles with energetic polymer as the oxidizer.
基金This work was supported by the Scientific Schools Development Program by Zelinsky Institute of organic chemistry(to A.B.S.,E.S.K.,R.E.N.and K.V.S.)。
文摘Progress in the rocket industry is only possible on the basis of new, higher performance and more environmentally friendly materials compared to up-to-date propellant ingredients for liquid, solid, gelled and hybrid propellant systems. In this work, synthetic methods have been developed for the preparation of new energetic azofurazans bearing nitroxymethyl or azidomethyl groups. All prepared compounds were fully characterized by multinuclear NMR and IR spectroscopies, as well as elemental analyses. An analysis of the structural features based on the X-ray single-crystal diffraction made it possible to discuss their influence on the densities of the azofurazans of this study. Thermal decomposition and combustion of nitroxymethyl and azidomethyl azofurazans were studied using a number of complementary experimental techniques, namely thermogravimetry, differential scanning calorimetry, manometry, microthermocouple measurements in the combustion wave. The structural and physical characteristics of these new energetic analogues illustrate the extent to which the nature of the explosophoric groups can be used to tune the performace of the azofurazan framework. These azofurazans possess positive calculated enthalpy of formation and are promising candidates for new environmentally friendly energetic materials.
文摘Different GAP-based CSRP samples with different binder contents were prepared and compared with that of conventional HTPB propellant.The crosslinker mixture of trimethylol propane(TMP)and butane diol(BD)was used in the GAP matrix beside the addition of dibutyltin dilaurate(DBTDL)to ensure cross-linking and curing completion of the prepared CSRP.The viscosity and hardness of all prepared formulations were monitored continuously during the curing process.The mechanical characteristics of cured samples were tested.The burning rate at operating pressure and specific impulse were measured,while the theoretical specific impulse(I sp)was calculated by ICT code and compared with the measured results.According to the results,DOA was found to be a suitable plasticizer for GAP when using in propellant.The mechanical properties of CSRP with 25%GAP can produce the optimum mechanical behavior,which is close to that of HTPB-based CSRP.The optimum GAP-based formulation is one candidate to replace the traditional HTPB-based CSRP with high burning rate for some applications.
