Aluminum nanoparticles,owing to their high energy density and excellent reactivity,are widely used to enhance the energy release efficiency of explosives.In this study,reactive molecular dynamics simulations were empl...Aluminum nanoparticles,owing to their high energy density and excellent reactivity,are widely used to enhance the energy release efficiency of explosives.In this study,reactive molecular dynamics simulations were employed to systematically investigate the hotspot evolution and reaction kinetics of aluminum nanoparticles under shock loading.The results show that hotspots predominantly form and evolve along the oxide layer interface,exhibiting a typical"hot shell-cold core"structure.A thicker oxide layer significantly delays the heating and reaction initiation of the aluminum core,with reversible crystal structure transformations observed inside the core.Larger particles facilitate heat accumulation and promote sustained reactions.As the oxide layer thickness increases,the reaction mechanism of aluminum nanoparticles transitions from melting-diffusion and micro-explosion oxidation to an oxidation-diffusion dominated process.A dense nitrogen-containing reaction layer forms on the surface,which suppresses the later-stage reaction.A nonlinear reaction kinetics model based on bond statistics reveals that particles with a thin oxide layer exhibit rapid reaction saturation and are insensitive to shock velocity.Particles with intermediate oxide thickness exhibit a reaction behavior that gradually slows down over time,while those with a thick oxide layer can exhibit accelerated reactions under high-velocity shocks due to enhanced diffusion.Small particles show significantly increased reaction rates at high velocities,whereas large particles tend to slow down due to the thickening of the surface reaction layer.The oxide layer thickness,particle size,and shock velocity exhibit complex competitive and synergistic effects that jointly regulate the initiation,rate,and evolution of aluminum nanoparticle reactions.展开更多
This study evaluates the stabilizing effect of lignin, extracted from Eucalyptus globulus, on an energetic composite of nitrated cellulose carbamate (NCC) plasticized with diethylene glycol dinitrate (DEGDN), compared...This study evaluates the stabilizing effect of lignin, extracted from Eucalyptus globulus, on an energetic composite of nitrated cellulose carbamate (NCC) plasticized with diethylene glycol dinitrate (DEGDN), compared to conventional stabilizers 2-nitrodiphenylamine (2-NDPA) and 1,3-dimethyl-1,3-diphenylurea (C-II). FTIR analysis confirms lignin's capacity to scavenge nitroxyl radicals formed during thermolysis of nitrocarbamate and nitrate ester bonds, thereby inhibiting decomposition. Moreover, the incorporation of C-II, 2-NDPA, and lignin significantly raised the peak temperature of the main thermolysis, as confirmed by DSC and TGA, indicating a progressive stability enhancement in the order: NCC/DEGDN < NCC/DEGDN/C-II < NCC/DEGDN/lignin < NCC/DEGDN/2-NDPA. Additionally, the effect of each stabilizer on the decomposition pathway was characterized by TGA-FTIR. The findings show that stabilizer type significantly affects the intensity of gaseous products released during decomposition without altering their nature. Notably, NH2 groups formed during NCC degradation play a key role in nitrogen conversion, particularly by reducing toxic NO emissions.展开更多
The efficient energy release of oxidizers and aluminum(Al)is of great significance in the field of high-energy propellants.Typically,the energy release efficiency of composite energetic materials is enhanced by improv...The efficient energy release of oxidizers and aluminum(Al)is of great significance in the field of high-energy propellants.Typically,the energy release efficiency of composite energetic materials is enhanced by improving the thermal decomposition and combustion of oxidizers or Al through the addition of catalytic materials.However,the catalysts primarily catalyze one of the components in composite en-ergetic materials.Developing a strategy to simultaneously enhance the energy release of oxidizers and Al using catalysts holds significant appeal.In this study,the Cobalt(Co)nanoparticle interface layer was constructed on the surface of Al powder through a one-step redox reaction to improve the decompo-sition and combustion performance of the oxidizer@Al composites.The Co nanoparticles with high reactivity act as"transport centers"facilitating the rapid transport of external oxygen to the internal active Al powder,thereby enhancing the thermal oxidation efficiency of the Al powder.The highly active Co nanoparticles also accelerate the ultrafast thermal decomposition of oxidizers,especially reducing the thermal decomposition temperature of ammonium perchlorate@Al@Co-30%from 397.04℃(AP@Al)to 311.69℃.It also promotes the accumulation of products during the thermal decomposition of the oxidizers,and the HCl content in DAP@Al@Co-10%and the NO_(2) content in AP@Al@Co-10%and CL 20@Al@Co-10%significantly increased during their thermal decomposition,further confirming the pronounced catalytic effect of Co nanoparticles.Furthermore,the synergistic catalytic effect of Co nanoparticle transit centers on Al powder and oxidizers also promotes the full combustion of oxi-dizer@Al energetic microunits,resulting in a significant decrease in combustion duration and an obvious increase in maximum flame area and flame growth rate of oxidizer@Al composite energetic microunits.In brief,the Co nanoparticle transit centers established in this study simultaneously en-hances the thermal decomposition and combustion properties of both Al powder and oxidizers,which is expected to significantly improve the energy release efficiency of propellants without changing their formulation.展开更多
The interfacial structure and its regulation play a crucial role in determining the overall performance of advanced functional composites.Weak interfacial interactions between carbon fibers and the matrix present a cr...The interfacial structure and its regulation play a crucial role in determining the overall performance of advanced functional composites.Weak interfacial interactions between carbon fibers and the matrix present a critical challenge limiting the general performance and functional applications of carbon fiberreinforced composites.In this paper,a novel strategy for bioinspired root-soil interfacial structure was presented to enhance the mechanical properties of polymer bonded explosives.A multiscale nanowire heterostructure was constructed through the in-situ growth of morphologically controllable zinc oxide nanowires on the carbon fiber surface via a facile hydrothermal method,with polydopamine as the interfacial reinforcement layer.This structure emulated the function of the"root",and combined with a network-distributed polymer binder representing the"soil",formed a robust root-soil interlocking interfacial structure within the polymer bonded explosives.Due to the multiscale interfacial reinforcement structure,the tensile strength of the polymer bonded explosives was visibly increased by 41%,the strain at the break by 110%,and the creep resistance by 51%with only 0.4 wt%filler adopted.The thermal stress resistance was improved by 57%owing to the synergistic enhancement of thermal conductivity and mechanical properties.This study provides new perspectives and insights for designing and constructing high-performance polymer bonded explosives and other functional composites.展开更多
This study presents a predictive model for condensed-phase heats of formation of metal-containing energetic complexes(MCECs)and energetic metal-organic frameworks(EMOFs),leveraging a dataset of 148 compounds.Using ele...This study presents a predictive model for condensed-phase heats of formation of metal-containing energetic complexes(MCECs)and energetic metal-organic frameworks(EMOFs),leveraging a dataset of 148 compounds.Using elemental composition,triazole rings,and metal presence,the model achieves high accuracy(R^(2)>0.94,mean absolute error(MAE)≈390 kJ/mol)for screening high-energy materials.It outperforms prior methods,particularly for polycyclic systems,offering a practical tool for safer design and risk assessment in defense and industrial applications.展开更多
Al/NH_(4)CoF_(3)-Φ(Φ=0.5,1.0,1.5,2.0,and 3.0)binary composites and Al-NH_(4)CoF_(3)@P(VDF-HFP)ternary composites are fabricated via ultrasonication-assisted blending and electrostatic spraying.The effect of equivale...Al/NH_(4)CoF_(3)-Φ(Φ=0.5,1.0,1.5,2.0,and 3.0)binary composites and Al-NH_(4)CoF_(3)@P(VDF-HFP)ternary composites are fabricated via ultrasonication-assisted blending and electrostatic spraying.The effect of equivalence ratio(Φ)on the reaction properties is systematically investigated in the binary Al/NH_(4)CoF_(3)system.For ternary systems,electrostatic spraying allows both components to be efficiently encapsulated by P(VDF-HFP)and to achieve structural stabilization and enhanced reactivity through synergistic interfacial interactions.Morphological analysis using SEM/TEM revealed that P(VDF-HFP)formed a protective layer on Al and NH_(4)CoF_(3)particles,improving dispersion,hydrophobicity(water contact angle increased by 80.5%compared to physically mixed composites),and corrosion resistance.Thermal decomposition of NH_(4)CoF_(3)occurred at 265℃,releasing NH_(3)and HF,which triggered exothermic reactions with Al.The ternary composites exhibited a narrowed main reaction temperature range and concentrated heat release,attributed to improved interfacial contact and polymer decomposition.Combustion tests demonstrated that Al-NH_(4)CoF_(3)@P(VDF-HFP)achieved self-sustaining combustion.In addition,a simple validation was done by replacing the Al component in the aluminium-containing propellant,demonstrating its potential application in the propellant field.This work establishes a novel strategy for designing stable,high-energy composites with potential applications in advanced propulsion systems.展开更多
Boron has attracted increasing attention in the field of high-energy explosives and propellants due to its high volume calorific value and mass calorific value.However,the complicated combustion process and low combus...Boron has attracted increasing attention in the field of high-energy explosives and propellants due to its high volume calorific value and mass calorific value.However,the complicated combustion process and low combustion efficiency hinder its wide application.To tackle this challenge,bioinspired polydopamine(PDA)interface reinforced boron-Viton composites,with high structure stability and excellent energy releasing efficiency,are designed and prepared,combining the interface regulation of PDA biomimetic materials and combustion promotion of fluoropolymers.Firstly,the stronger adsorption energy of PDA with boron compared to Viton is demonstrated by molecular dynamics simulations.Next,B@PDA@Viton is prepared by the combination of in-situ dopamine polymerization and solvent/nonsolvent method,and the double-layer core-shell structure is confirmed by XPS,FTIR,and TEM characterizations.TG-DSC analysis shows that B@PDA@Viton possesses superior thermal properties,with a 55.48%increase in oxidation heat compared to raw B.Furthermore,ignition and combustion performance tests indicate that B@PDA@Viton reduces ignition delay by 57.56%and increases heat of combustion by 68.63%relative to raw B.These findings elucidate the ignition and combustion mechanisms of B@PDA@Viton.This work not only developed high-performance boron-based composite fuels but also provided insights into the development of boron-based fuels.展开更多
Primary explosives generally play a critical role in initiating explosive reactions in energetic systems,where thermal initiation is governed by the stability of structural hot-spot bonds.However,the sub-sequent defla...Primary explosives generally play a critical role in initiating explosive reactions in energetic systems,where thermal initiation is governed by the stability of structural hot-spot bonds.However,the sub-sequent deflagration pathway following the thermal initiation has been always overlooked.Some ex-plosives with weak hot-spot bond strength,nonetheless,undergo a stable deflagration process until detonation occurs,indicating the strength of hot-spot bond is insufficient to evaluate the performance prior to detonation.Here,based on the recently synthesized crystalline[Cu(1-MTZ)_(4)(ClO_(3))_(2)],we construct 1-methyltetrazole(1-MTZ)metal complexes[M(1-MTZ)_(4)(ClO_(3))_(2)](M=Mn^(2+),Fe^(2+),Co^(2+),Ni^(2+),Cu^(2+),and Zn^(2+))to investigate the role of center metal in both the thermal initiation and the following deflagration process.Density functional theory(DFT)and Car Parrinello molecular dynamics(CPMD)methods are applied to establish the relationship between the coordinative bond strength/metal sta-bilization energy and initial dynamic performances.This study reveals that the initial decomposition stage should encompass both the initiation process and the pre-detonation deflagration process,with both processes being regulated by the characteristics of different transition metal centers.Instead of relying on a one-dimensional evaluation approach focused solely on"hot-spot"sites,this study es-tablishes a novel framework for assessing the stability of the entire initial decomposition process.展开更多
As a prototypical high-energy-density reactive material system,metastable intermolecular composites(MICs)have attracted considerable interest owing to their customizable component configurations and interfacial archit...As a prototypical high-energy-density reactive material system,metastable intermolecular composites(MICs)have attracted considerable interest owing to their customizable component configurations and interfacial architectures.Nevertheless,their energy release characteristics are fundamentally constrained by the formation of condensed-phase products with elevated boiling points,thereby diminishing their efficacy in applications requiring rapid pressure generation or shock wave propagation.Herein,we demonstrate a molecular-level fluorination approach that enables oxygen substitution by fluorine within bismuth oxide crystalline frameworks,yielding ternary BixOyFz crystals with atomically precise F/O stoichiometric control through systematic solvent polarity engineering.This energetics system,designed through a multilevel regulation strategy,realizes stepwise redox reactions of Al–F and Al–O during energy release,with the partitioning between these redox pathways being precisely allocable through hierarchical regulation.Furthermore,the pre-ignition reaction(PIR)between BixOyFz and Al2O3(the inert passivation shell of Al)weakens the passivation layer,lowering the ignition threshold.The in situ generation of low-boiling-point AlF3 promotes rapid gas expansion,leading to significantly enhanced pressurization rates and deflagration wave velocities under confinement compared to conventional strategies.To evaluate energy output capabilities and validate potential safety-protection applications,the system successfully achieved instantaneous destruction of SD chips,enabling secure data erasure.This work establishes crystalline lattice fluorination as a generalized materials design strategy to transcend intrinsic limitations of MICs systems in component selection and reaction thermodynamics,providing new paradigms for adaptive energetic architectures and transient microelectromechanical applications.展开更多
To elucidate the dispersion and explosion characteristics of multi-metal powder and liquid composite fuel formulations,high-energy metal powders(aluminum(Al),boron(B),and magnesium hydride(MgH_(2)))are incorporated in...To elucidate the dispersion and explosion characteristics of multi-metal powder and liquid composite fuel formulations,high-energy metal powders(aluminum(Al),boron(B),and magnesium hydride(MgH_(2)))are incorporated into a liquid fuel primarily composed of diethyl ether(DEE)and isopropyl nitrate(IPN).The explosion characteristics of different solid-liquid fuel-air-explosive(FAE)under unconfined conditions are investigated using a high-speed camera,infrared thermal imaging,and a pressure measurement system.Results demonstrate that high-energy metal powders significantly enhance detonation energy dissipation,with aluminum exhibiting the most pronounced effect.Fuel 5#(45.4 wt%DEE,9.2 wt%IPN,29.5 wt%Al,9.1 wt%B,6.8 wt%MgH_(2))exhibits superior explosion performance,achieving higher values of overpressure,impulse,and thermal radiation damage during the detonation stage compared to other fuels.However,Fuel 5#also displays faster decay rates,attributed to accelerated heat release rates induced by B and MgH_(2)powders.This study reveals that different metal powders in solid-liquid FAE exhibit distinct enhancements in explosion performance,providing critical insights for optimizing composite fuel design.展开更多
基金supported by the State Key Program of National Natural Science Foundation of China(No.12272051)the BIT Research and Innovation Promoting Project(No.2023YCXY17).
文摘Aluminum nanoparticles,owing to their high energy density and excellent reactivity,are widely used to enhance the energy release efficiency of explosives.In this study,reactive molecular dynamics simulations were employed to systematically investigate the hotspot evolution and reaction kinetics of aluminum nanoparticles under shock loading.The results show that hotspots predominantly form and evolve along the oxide layer interface,exhibiting a typical"hot shell-cold core"structure.A thicker oxide layer significantly delays the heating and reaction initiation of the aluminum core,with reversible crystal structure transformations observed inside the core.Larger particles facilitate heat accumulation and promote sustained reactions.As the oxide layer thickness increases,the reaction mechanism of aluminum nanoparticles transitions from melting-diffusion and micro-explosion oxidation to an oxidation-diffusion dominated process.A dense nitrogen-containing reaction layer forms on the surface,which suppresses the later-stage reaction.A nonlinear reaction kinetics model based on bond statistics reveals that particles with a thin oxide layer exhibit rapid reaction saturation and are insensitive to shock velocity.Particles with intermediate oxide thickness exhibit a reaction behavior that gradually slows down over time,while those with a thick oxide layer can exhibit accelerated reactions under high-velocity shocks due to enhanced diffusion.Small particles show significantly increased reaction rates at high velocities,whereas large particles tend to slow down due to the thickening of the surface reaction layer.The oxide layer thickness,particle size,and shock velocity exhibit complex competitive and synergistic effects that jointly regulate the initiation,rate,and evolution of aluminum nanoparticle reactions.
文摘This study evaluates the stabilizing effect of lignin, extracted from Eucalyptus globulus, on an energetic composite of nitrated cellulose carbamate (NCC) plasticized with diethylene glycol dinitrate (DEGDN), compared to conventional stabilizers 2-nitrodiphenylamine (2-NDPA) and 1,3-dimethyl-1,3-diphenylurea (C-II). FTIR analysis confirms lignin's capacity to scavenge nitroxyl radicals formed during thermolysis of nitrocarbamate and nitrate ester bonds, thereby inhibiting decomposition. Moreover, the incorporation of C-II, 2-NDPA, and lignin significantly raised the peak temperature of the main thermolysis, as confirmed by DSC and TGA, indicating a progressive stability enhancement in the order: NCC/DEGDN < NCC/DEGDN/C-II < NCC/DEGDN/lignin < NCC/DEGDN/2-NDPA. Additionally, the effect of each stabilizer on the decomposition pathway was characterized by TGA-FTIR. The findings show that stabilizer type significantly affects the intensity of gaseous products released during decomposition without altering their nature. Notably, NH2 groups formed during NCC degradation play a key role in nitrogen conversion, particularly by reducing toxic NO emissions.
基金supported by the National Natural Science Foundation of China(Grant No.22375098)the Joint Funds of the National Natural Science Foundation of China(Grant No.U2141202)the Fundamental Research Funds for the Central Uni-versities(Grant No.30925020105).
文摘The efficient energy release of oxidizers and aluminum(Al)is of great significance in the field of high-energy propellants.Typically,the energy release efficiency of composite energetic materials is enhanced by improving the thermal decomposition and combustion of oxidizers or Al through the addition of catalytic materials.However,the catalysts primarily catalyze one of the components in composite en-ergetic materials.Developing a strategy to simultaneously enhance the energy release of oxidizers and Al using catalysts holds significant appeal.In this study,the Cobalt(Co)nanoparticle interface layer was constructed on the surface of Al powder through a one-step redox reaction to improve the decompo-sition and combustion performance of the oxidizer@Al composites.The Co nanoparticles with high reactivity act as"transport centers"facilitating the rapid transport of external oxygen to the internal active Al powder,thereby enhancing the thermal oxidation efficiency of the Al powder.The highly active Co nanoparticles also accelerate the ultrafast thermal decomposition of oxidizers,especially reducing the thermal decomposition temperature of ammonium perchlorate@Al@Co-30%from 397.04℃(AP@Al)to 311.69℃.It also promotes the accumulation of products during the thermal decomposition of the oxidizers,and the HCl content in DAP@Al@Co-10%and the NO_(2) content in AP@Al@Co-10%and CL 20@Al@Co-10%significantly increased during their thermal decomposition,further confirming the pronounced catalytic effect of Co nanoparticles.Furthermore,the synergistic catalytic effect of Co nanoparticle transit centers on Al powder and oxidizers also promotes the full combustion of oxi-dizer@Al energetic microunits,resulting in a significant decrease in combustion duration and an obvious increase in maximum flame area and flame growth rate of oxidizer@Al composite energetic microunits.In brief,the Co nanoparticle transit centers established in this study simultaneously en-hances the thermal decomposition and combustion properties of both Al powder and oxidizers,which is expected to significantly improve the energy release efficiency of propellants without changing their formulation.
基金supported by the Presidential Foundation of CAEP(No.YZJJZQ2022006)the National Natural Science Foundation of China(Nos.22275173 and 22475179).
文摘The interfacial structure and its regulation play a crucial role in determining the overall performance of advanced functional composites.Weak interfacial interactions between carbon fibers and the matrix present a critical challenge limiting the general performance and functional applications of carbon fiberreinforced composites.In this paper,a novel strategy for bioinspired root-soil interfacial structure was presented to enhance the mechanical properties of polymer bonded explosives.A multiscale nanowire heterostructure was constructed through the in-situ growth of morphologically controllable zinc oxide nanowires on the carbon fiber surface via a facile hydrothermal method,with polydopamine as the interfacial reinforcement layer.This structure emulated the function of the"root",and combined with a network-distributed polymer binder representing the"soil",formed a robust root-soil interlocking interfacial structure within the polymer bonded explosives.Due to the multiscale interfacial reinforcement structure,the tensile strength of the polymer bonded explosives was visibly increased by 41%,the strain at the break by 110%,and the creep resistance by 51%with only 0.4 wt%filler adopted.The thermal stress resistance was improved by 57%owing to the synergistic enhancement of thermal conductivity and mechanical properties.This study provides new perspectives and insights for designing and constructing high-performance polymer bonded explosives and other functional composites.
文摘This study presents a predictive model for condensed-phase heats of formation of metal-containing energetic complexes(MCECs)and energetic metal-organic frameworks(EMOFs),leveraging a dataset of 148 compounds.Using elemental composition,triazole rings,and metal presence,the model achieves high accuracy(R^(2)>0.94,mean absolute error(MAE)≈390 kJ/mol)for screening high-energy materials.It outperforms prior methods,particularly for polycyclic systems,offering a practical tool for safer design and risk assessment in defense and industrial applications.
基金supported by the National Natural Science Foundation of China(No.51706105)。
文摘Al/NH_(4)CoF_(3)-Φ(Φ=0.5,1.0,1.5,2.0,and 3.0)binary composites and Al-NH_(4)CoF_(3)@P(VDF-HFP)ternary composites are fabricated via ultrasonication-assisted blending and electrostatic spraying.The effect of equivalence ratio(Φ)on the reaction properties is systematically investigated in the binary Al/NH_(4)CoF_(3)system.For ternary systems,electrostatic spraying allows both components to be efficiently encapsulated by P(VDF-HFP)and to achieve structural stabilization and enhanced reactivity through synergistic interfacial interactions.Morphological analysis using SEM/TEM revealed that P(VDF-HFP)formed a protective layer on Al and NH_(4)CoF_(3)particles,improving dispersion,hydrophobicity(water contact angle increased by 80.5%compared to physically mixed composites),and corrosion resistance.Thermal decomposition of NH_(4)CoF_(3)occurred at 265℃,releasing NH_(3)and HF,which triggered exothermic reactions with Al.The ternary composites exhibited a narrowed main reaction temperature range and concentrated heat release,attributed to improved interfacial contact and polymer decomposition.Combustion tests demonstrated that Al-NH_(4)CoF_(3)@P(VDF-HFP)achieved self-sustaining combustion.In addition,a simple validation was done by replacing the Al component in the aluminium-containing propellant,demonstrating its potential application in the propellant field.This work establishes a novel strategy for designing stable,high-energy composites with potential applications in advanced propulsion systems.
基金funded by the National Natural Science Foundation of China,Grant No.22405208。
文摘Boron has attracted increasing attention in the field of high-energy explosives and propellants due to its high volume calorific value and mass calorific value.However,the complicated combustion process and low combustion efficiency hinder its wide application.To tackle this challenge,bioinspired polydopamine(PDA)interface reinforced boron-Viton composites,with high structure stability and excellent energy releasing efficiency,are designed and prepared,combining the interface regulation of PDA biomimetic materials and combustion promotion of fluoropolymers.Firstly,the stronger adsorption energy of PDA with boron compared to Viton is demonstrated by molecular dynamics simulations.Next,B@PDA@Viton is prepared by the combination of in-situ dopamine polymerization and solvent/nonsolvent method,and the double-layer core-shell structure is confirmed by XPS,FTIR,and TEM characterizations.TG-DSC analysis shows that B@PDA@Viton possesses superior thermal properties,with a 55.48%increase in oxidation heat compared to raw B.Furthermore,ignition and combustion performance tests indicate that B@PDA@Viton reduces ignition delay by 57.56%and increases heat of combustion by 68.63%relative to raw B.These findings elucidate the ignition and combustion mechanisms of B@PDA@Viton.This work not only developed high-performance boron-based composite fuels but also provided insights into the development of boron-based fuels.
基金the National Natural Science Foundation of China(Grant No.21701001)the opening project of State Key Laboratory of Explo-sion Science and Safety Protection(Beijing Institute of Technology,Grant No.KFJJ24-15M)the University Natural Science Research Project of Anhui Province(Grant No.KJ2020ZD04).
文摘Primary explosives generally play a critical role in initiating explosive reactions in energetic systems,where thermal initiation is governed by the stability of structural hot-spot bonds.However,the sub-sequent deflagration pathway following the thermal initiation has been always overlooked.Some ex-plosives with weak hot-spot bond strength,nonetheless,undergo a stable deflagration process until detonation occurs,indicating the strength of hot-spot bond is insufficient to evaluate the performance prior to detonation.Here,based on the recently synthesized crystalline[Cu(1-MTZ)_(4)(ClO_(3))_(2)],we construct 1-methyltetrazole(1-MTZ)metal complexes[M(1-MTZ)_(4)(ClO_(3))_(2)](M=Mn^(2+),Fe^(2+),Co^(2+),Ni^(2+),Cu^(2+),and Zn^(2+))to investigate the role of center metal in both the thermal initiation and the following deflagration process.Density functional theory(DFT)and Car Parrinello molecular dynamics(CPMD)methods are applied to establish the relationship between the coordinative bond strength/metal sta-bilization energy and initial dynamic performances.This study reveals that the initial decomposition stage should encompass both the initiation process and the pre-detonation deflagration process,with both processes being regulated by the characteristics of different transition metal centers.Instead of relying on a one-dimensional evaluation approach focused solely on"hot-spot"sites,this study es-tablishes a novel framework for assessing the stability of the entire initial decomposition process.
基金supported by the National Natural Science Foundation of China,China(Grant No.22305100,No.22405104)the Hubei Provincial International Science and Technology Cooperation Program Project(Grant No.2023EHA014)+4 种基金the National Foreign Experts Program(Grant No.Y20240022,H20240275)the Hubei Natural Science Foundation(Grant No.2025AFB460)the Hubei Provincial Department of Education Scientific Research Project(Grant No.F2023033,Q20234414)the Wuhan Natural Science Foundation Exploration Project(Chenguang Program)(Grant No.2025040601020173)the Jianghan University Scientific Research Startup Fund(Grant No.PBSKL-2022-QD-08,No.PBSKL-2024-QD-03).
文摘As a prototypical high-energy-density reactive material system,metastable intermolecular composites(MICs)have attracted considerable interest owing to their customizable component configurations and interfacial architectures.Nevertheless,their energy release characteristics are fundamentally constrained by the formation of condensed-phase products with elevated boiling points,thereby diminishing their efficacy in applications requiring rapid pressure generation or shock wave propagation.Herein,we demonstrate a molecular-level fluorination approach that enables oxygen substitution by fluorine within bismuth oxide crystalline frameworks,yielding ternary BixOyFz crystals with atomically precise F/O stoichiometric control through systematic solvent polarity engineering.This energetics system,designed through a multilevel regulation strategy,realizes stepwise redox reactions of Al–F and Al–O during energy release,with the partitioning between these redox pathways being precisely allocable through hierarchical regulation.Furthermore,the pre-ignition reaction(PIR)between BixOyFz and Al2O3(the inert passivation shell of Al)weakens the passivation layer,lowering the ignition threshold.The in situ generation of low-boiling-point AlF3 promotes rapid gas expansion,leading to significantly enhanced pressurization rates and deflagration wave velocities under confinement compared to conventional strategies.To evaluate energy output capabilities and validate potential safety-protection applications,the system successfully achieved instantaneous destruction of SD chips,enabling secure data erasure.This work establishes crystalline lattice fluorination as a generalized materials design strategy to transcend intrinsic limitations of MICs systems in component selection and reaction thermodynamics,providing new paradigms for adaptive energetic architectures and transient microelectromechanical applications.
基金supported by the National Natural Science Foundation of China(Grant No.12402432)Natural Science Foundation of Jiangsu Province of China(Grant No.BK20230936)Graduate Education and Teaching Reform Project of Nanjing University of Science and Technology(Grant No.KT2024_C14)。
文摘To elucidate the dispersion and explosion characteristics of multi-metal powder and liquid composite fuel formulations,high-energy metal powders(aluminum(Al),boron(B),and magnesium hydride(MgH_(2)))are incorporated into a liquid fuel primarily composed of diethyl ether(DEE)and isopropyl nitrate(IPN).The explosion characteristics of different solid-liquid fuel-air-explosive(FAE)under unconfined conditions are investigated using a high-speed camera,infrared thermal imaging,and a pressure measurement system.Results demonstrate that high-energy metal powders significantly enhance detonation energy dissipation,with aluminum exhibiting the most pronounced effect.Fuel 5#(45.4 wt%DEE,9.2 wt%IPN,29.5 wt%Al,9.1 wt%B,6.8 wt%MgH_(2))exhibits superior explosion performance,achieving higher values of overpressure,impulse,and thermal radiation damage during the detonation stage compared to other fuels.However,Fuel 5#also displays faster decay rates,attributed to accelerated heat release rates induced by B and MgH_(2)powders.This study reveals that different metal powders in solid-liquid FAE exhibit distinct enhancements in explosion performance,providing critical insights for optimizing composite fuel design.
