Impact Sensitivity Research Articles

Hexanitrostilbene (HNS) is an explosive characterized by low mechanical sensitivity, high thermal stability, and excellent physicochemical and radiation resistance. It is widely used in both military and civilian applications. HNS-IV, known for its appropriate impact sensitivity to narrow pulse detonation, is currently the primary filling in shock wave detonators. However, due to the large specific surface area and high surface activity of ultrafine HNS-IV, it exhibits significant static electricity and poor flowability, which adversely affect the accuracy of its mass loading and subsequently density. To address the issues of poor flowability and moldability between ultrafine HNS-IV particles, this study utilized molecular dynamics simulations to select a high-performance, heat-resistant binder. Using this binder and graphite as an antistatic agent, a modified sample of ultrafine HNS-IV was prepared via the solvent evaporation method. The modified and unmodified samples were then subjected to comprehensive tests for morphology and composition, differential scanning calorimetry (DSC), repose angle, bulk density, explosion point, and charge amount. Using molecular dynamics (MD) methods within the Materials Studio software, we computed the binding energies, initiation bond lengths, and mechanical properties of four types of polymer-bonded explosives (PBX) following a 1 ns NPT dynamic simulation. The MD simulation was conducted over a total duration of 1 ns with a time step of 1 fs. The simulations utilized the COMPASS force field, and the temperature was maintained at 298 K.

Impact Sensitivity Test and Ignition Response Simulation of HMX/Al/HTPB Cast PBX Tablet by Drop Hammer

Innovative energy storage technologies in the energetic materials field represent a critical frontier in energy research. Consequently, we developed a performance regulation strategy based on tetrazolyl high-energy-density energy storage molecular systems and theoretically assessed their energetic properties and safety profiles. The findings reveal that substituent characteristics profoundly affect the performances of these energy storage molecular systems. The molecule systems ((1-amino-1H-tetrazol-5-yl)azanediyl)bis(1H-tetrazole-5,1-diyl) dinitrate, ((1-azido-1H-tetrazol-5-yl)azanediyl)bis(1H-tetrazole-5,1-diyl) dinitrate, ((1-nitro-1H-tetrazol-5-yl)azanediyl)bis(1H-tetrazole-5,1-diyl) dinitrate, and especially ((1-azido-1H-tetrazol-5-yl)azanediyl)bis(1H-tetrazole-5,1-diyl) dinitrate, exhibit exceptional performances, including high density, high heat of formation, high detonation velocity and pressure, zero oxygen balance, and low impact sensitivity, qualifying them as high-energy-density and low-sensitivity candidates. This work offers novel pathways for advancing energy storage technologies in energetic materials field.

ABSTRACT A series of K‐6 based energetic compounds are designed by the addition of the characteristic structures of NQ and FOX‐7. Density functional theory calculations at the B3LYP/6‐311G(d,p) level are performed to predict the frontier orbital energy, heats of formation, detonation performance, and impact sensitivity of the designed compounds. It is found that compound C3 possesses the highest value of Δ E LUMO‐HOMO (5.24 eV), whereas that of compound E6 is the lowest (2.86 eV). Compound C4 has the highest values of Δ H f,solid (1768.0 kJ mol −1 ) while that of compound D5 possesses the lowest values (431.1 kJ mol −1 ). It is concluded that the addition of the N 3 group combined with the tetrazole ring and NQ structure can improve the values of heats of formation effectively. It is also found that compounds F2 and B3 possess the maximum and minimum values of D and P (compound F2: D, 9.65 km s −1 , P, 44.0 GPa; compound B3: D, 7.60 km s −1 , P, 25.0 GPa). There exist 24 compounds that possess higher values of h 50 than that of RDX, whereas there are 16 compounds that possess higher values of h 50 than that of HMX. Finally, compounds A7, A8, and D1 are screened as potential high energy density compounds. Their frontier orbital distribution, thermodynamic properties, electrostatic potential distribution, and area are simulated to give a full understanding of the electronic structure and physicochemical properties of the screened compounds.

ABSTRACT To make the search for new energetic materials more efficient and foster progress in the development of structure–property relationships, a number of misconceptions are highlighted. They pertain to the influence on performances and sensitivities of fundamental material properties, including formation enthalpy and density and to that of molecular descriptors, such as molecular size. Regarding impact sensitivity, as measured in the drop weight impact test, ambiguities arising from the use of different experimental setups are emphasized, and consequences on the modeling of this property are illustrated. Regarding thermal stability, we highlight the significance of considering the melting point, in addition to decomposition temperature. Finally, the application of molecular modeling tools to the design of polymer‐bonded explosives is discussed.

ABSTRACT This study mainly explored the performance characteristics of RDX‐based gun propellants using glycidyl azide polymer‐energetic thermoplastic elastomer (GAP‐ETPE) as an energetic plasticizer by experimental method. Four formulations were selected to prepare test samples based on the formulation of the M26 gun propellant. RDX and GAP‐ETPE were used to replace NQ (Nitroguanidine) and reduce the nitrocellulose content in the formulation of M26 gun propellant. The thermochemical characteristics, explosion heat, chemical stability, impact, friction, and electrostatic spark sensitivities, compressive strength, and combustion performance of these four test samples were determined by various instruments. The experimental results indicated that the addition of GAP‐ETPE can reduce the decomposition temperature and activation energy of RDX in RDX‐based gun propellants. The explosion heat of four RDX‐based gun propellant samples with GAP‐ETPE as the energetic plasticizer is close to that of M26 gun propellant. They have good chemical stability and are less sensitive than M26 gun propellant because they do not contain nitroglycerin. In addition, their maximum stress is close to that of M26 gun propellant, and their maximum strain is better than that of M26 gun propellant. The combustion performance tests indicated that samples A and C have the potential to replace the M26 gun propellant, but further live‐fire tests are needed for verification.

Regioisomeric control is presented as a precise strategy to resolve the energy-stability conflict in trifunctionalized 1,2,4-triazole energetic materials. By positioning a stabilizing amino group adjacent to a highly energetic trinitromethyl group, a new molecule, 1-trinitromethyl-3-nitro-5-amino-1,2,4-triazole (TN-ANTA), was designed and synthesized. Compared to its reported isomer, TN-ANTA exhibits a superior combination of high density (1.905 g/cm3 vs 1.878 g/cm3), enhanced thermal stability (Tdec = 128 °C vs 119 °C), and markedly improved impact sensitivity (7 J vs 1 J). Mechanistic studies reveal that this enhancement stems from a combination of more compact crystal packing, driven by stronger intermolecular interactions, and a higher bond dissociation energy of the weakest C-NO2 bond due to intramolecular stabilization. The superiority of this design principle was further validated as the energetic salts of TN-ANTA also consistently displayed higher densities and thermal stabilities than their corresponding isomers. This work establishes regioisomeric placement of functional groups as a powerful approach for the rational design of advanced energetic materials.

ABSTRACT In this computational study, we designed four nitrogen‐rich adamantane derivatives based carbocyclic cage compounds that serve as versatile platforms for the design and development of explosives with tailored properties. We explore the Incorporation of four different explosophoric groups on the hexaazaadamantane skeleton e.g. ─N(O)─NNO 2 , ─N(O)─NCN, ─N 3 , and ─ONO 2 functionalities, renowned for their high energy content and ability to enhance explosive properties. Theoretically, using DFT, we predict the electronic structure, heat of formation, thermodynamic stability, impact sensitivity, and detonation performance of these azaadamantane derivatives. All the compounds have high density and good detonation properties. The compound M4 exhibits the highest detonation pressure (48.39 GPa), detonation velocity (9.92 km/s), and density (2.12 g/cm 3 ), surpassing conventional explosives like HMX and CL20. Compound M3 shows the highest heat of combustion (1993.84 cal/g), while M1 demonstrates notable brisance (215.39 mm). Moreover, the studied compounds exhibit superior thermal stability and explosive performance compared to CL‐20. The results indicate that these kinds of hexaazaadamantane derivatives might be useful for developing novel energetic compounds with excellent detonation performance and low sensitivity.

The reduction of mechanical sensitivity in energetic materials is a critical safety concern. This research demonstrates that the temperature-induced polymorphic transition in 1,1-diamino-2,2-dinitroethene (FOX-7) is an effective method for desensitization. By employing in-situ X-ray diffraction and elevated-temperature impact tests, we reveal that the β-phase of FOX-7, which is attained at temperatures exceeding 116 °C, shows significantly diminished impact sensitivity. The characteristic drop height (H50) of unmodified FOX-7 increases substantially following the α to β transition, with a 57% enhancement noted at 126 °C compared to the baseline at ambient temperature. This improvement in safety is attributed to structural reorganization and alterations in hydrogen-bonding configurations that facilitate more efficient energy dissipation pathways. Additionally, the application of a polydopamine (PDA) coating combined with a fluoropolymer (F2314) binder further elevates the H50 value to 111.6 cm at 126 °C, thereby enhancing safety while maintaining energetic performance. A finite-element thermo-mechanical model was developed to accurately predict the kinetics of phase transition and stress evolution, providing a computational framework for the optimization of formulations. These findings highlight the potential of phase-transition engineering as a promising strategy for the development of intrinsically safer high-energy materials.

Understanding the Correlation between Impact Sensitivity and Elasticity of Energetic Crystals via Dispersion-Corrected Density Functional Theory Calculations

Abstract This study investigates the factors influencing the predictive power of B-ultrasound imaging in assessing semen quality in young boars. Semen quality is a key factor in animal breeding, directly influencing reproductive success and herd productivity. While advances in molecular evaluation and cryopreservation have improved breeding outcomes, traditional fertility assessments remain resource-intensive. Deep learning (DL) has revolutionized medical imaging and presents new opportunities for veterinary applications, including reproductive assessments via ultrasound. However, its application to B-ultrasound imaging in boars remains underexplored. This study addresses this gap by using DL models to analyze testicular ultrasound features for predicting semen quality more efficiently. A total of 107 boars born in 2021 were examined using an IMV Technologies ExaPad Mini ultrasound system under standardized imaging settings. Each boar was scanned to collect 9–17 images, resulting in a dataset of 1,417 images. Semen quality data, including sperm concentration, motility, morphology, and volume, were collected biweekly to monthly throughout 2022. Boars were classified based on industry standards, requiring a total sperm count of ≥ 20 × 10⁹, motility ≥ 70%, and morphology ≥ 70% from collections between 200 and 540 days of age. Those consistently meeting these criteria were categorized as high-quality semen boars (n = 82), while those with at least 10% of collections failing to meet the standards or flagged for semen quality issues were classified as underperforming (n = 25). DL models (YOLOv11n and YOLOv11m) were trained and validated using a random image data-splitting method. Image preprocessing involved cropping to focus on seminiferous tubules and applying brightness augmentation. Model performance, measured by precision and recall, was analyzed using ANOVA. Results indicate that full images, the vertical angle, and avoiding brightness augmentation optimize model performance. Brightness augmentation significantly reduced precision (p < 0.001), leading to a 3.34% decline. Cropping negatively impacted sensitivity (p < 0.001, coefficient = -0.2049), while the vertical angle improved it (p < 0.001, coefficient = 0.1302). The YOLOv11m model had a slightly higher Recall than YOLOv11n, but the difference was not statistically significant (p = 0.548). In conclusion, the strong performance of full images suggests that areas beyond the seminiferous tubules contribute to semen quality prediction. The vertical angle likely captures more relevant details than the horizontal angle, as it provides a clearer view of the rete testis structure. Additionally, the precision drop with brightness augmentation highlights the importance of preserving natural brightness levels. This study shows that optimizing image selection and acquisition enhances ultrasound-based semen quality prediction in boars.

To improve the safety of cyclotetramethylenetetranitramine (HMX) particles, the polymer thermoplastic polyurethane elastomer (TPU) and nitrocellulose (NC) were introduced to coat HMX powder by water-solution suspension method and internal solution method, respectively. Scanning electron microscope (SEM) and X-ray photo-electron spectrometry (XPS) were employed to characterize the HMX samples and the role of NC and TPU in the coating processes were discussed. The impact sensitivity, friction sensitivity, and the thermal decomposition of coated HMX particles were investigated, and compared to the unprocessed ones. The results indicate that both TPU and NC can improve the wetting ability of the coating materials on HMX surface and reinforce the connection between HMX and the coating materials. The impact sensitivity and friction sensitivity of HMX samples decrease obviously after they have been surface coated; the drop height (H50) is increased from 35.24 cm to 50.08 cm, and the friction probability is reduced from 93.2 % to 58.3%. The activation energy (Ea) and the self-ignition temperature increase by 10.46 KJ·mol-1 and 1.8, respectively.

To explore a new functional explosive with improved safety performance, this study synthesized a hydrated salt-based phase change composite (PCC) using magnesium sulfate heptahydrate and ammonium aluminum sulfate dodecahydrate as raw materials. Additionally, HMX/F2602/PCC composite microspheres were prepared via spray drying. The HMX/F2602/PCC composite microspheres were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and impact sensitivity testing. The results indicate that HMX/F2602/PCC composite microspheres exhibit superior morphology and safety, compared with HMX/F2602 composite microspheres. Under the premise that the thermal sensitivity of HMX-based PBX remains essentially unchanged, the apparent activation energy decreases by 34.46 kJ/mol and 58.85 kJ/mol when the PCC content is 1% and 1.5%, respectively. Moreover, compared with HMX/F2602 composite microspheres, the characteristic drop heights of HMX/F2602/PCC composite microspheres with three different mass ratios increase by 5.72 cm, 10.55 cm, and 14.68 cm, respectively. Correspondingly, their impact sensitivity is significantly reduced, and their safety performance is notably improved.

Unraveling the impact sensitivity mechanism of energetic materials from vibrational and electronic energy transfer

As the first metal-free molecular perovskite energetic material, (H2dabco)[NH4(ClO4)3]DAP-4 has attracted significant research interest globally for its excellent thermal stability, superior detonation performance, and good moisture resistance. The crystal form of energetic materials plays a crucial role in determining the energy output and safety performance. To obtain spherical DAP-4 crystal particles, the effect of different solvents on the growth morphology of DAP-4 was studied. Based on the simulation and experimental results, a suitable mixed solvent system was selected, and spherical DAP-4 was successfully prepared by the solvent-etching method. The influence of process parameters on the morphology and particle size of DAP-4 crystals was studied. The morphology and particle size distribution of DAP-4 crystals were characterized, and the thermal decomposition behavior, combustion properties, and mechanical sensitivity of spherical DAP-4 were examined and discussed. The results show that spherical DAP-4 can be obtained under conditions of a solvent/nonsolvent volume ratio of 1:2, a temperature of 40 °C, and an experimental duration of 3 h. Compared to raw DAP-4, the bulk density and tapped density of spherical DAP-4 increased by 35.1% and 11.0%, respectively. The thermal decomposition peak temperature of spherical DAP-4 is close to that of raw DAP-4, indicating that spheroidization did not reduce the thermal stability of DAP-4. The combustion performance of spherical DAP-4 was significantly improved. In addition, the impact sensitivity of spherical DAP-4 increased by 23.17%, and the probability of explosion decreased by 12% compared to raw DAP-4. Based on these findings, a sensitivity-reducing mechanism for spherical DAP-4 was proposed.

This research explores the impact of systematic addition of pentazole group on the explosive properties of prismane-based compounds on hexanitroprismane and hexaminoprismane. Replacing the NO2 and NH2 groups with N5 in prismane cage-based molecules enhances the material's energy density and stability, leading to more powerful and stable explosives. The structure-property relationship of the designed molecules is studied using DFT approach. These cage-based compounds exhibit potential as high-energy density explosive compounds reaching up to the level of CL20. Systematic addition of pentazole ring in the prismane cage improves stability and heat of formation. Functionalizing prismane with one pentazole ring can improve the HOF by 300 to 400 kJmol-1. The impact of the number of pentazole rings on density is opposite in nature in -NO2 and -NH2 containing sets of molecules. The same trend is observed in the values of D, P, and Q of both sets of molecules as the number of pentazole group increased in the prismane. Insertion of a single pentazole ring in prismane for the nitro group substituted molecules has a better impact on improving the impact sensitivity. Pentazole group substitution enhances the energetic properties of prismane-based high energy density compounds, offering a promising avenue for the development of novel, high-performance explosives with tailored detonation characteristics. Density functional theory (DFT) using Gaussian 16 software was used for all quantum chemical calculations. The optimization of the geometry of the designed compounds is performed at two different levels, e.g., B3LYP/6-311 + + G(d,p) and B3PW91/6-31G(d,p). Molecular surface and other properties are visualized using GaussView 6.0 software. The heat of formation (HOF) of the molecules is estimated using isodesmic reactions. The multiwfn program was used for the calculation of molecular surface properties.

The oxygen balance (OB) of energetic materials plays a critical role in determining the efficiency and effectiveness of energy release during combustion or detonation. To enhance the OB and comprehensive properties of 3-picrylamino-1,2,4-triazole (PATO), which is a high-energy and low-sensitivity explosive, this study employed a self-assembly strategy to combine nitric acid with PATO, resulting in a novel 3-picrylamino-1,2,4-triazole-nitric acid self-assembled energetic material (PATO-N). Its structure was characterized by single crystal X-ray diffraction, and the thermal decomposition properties and impact sensitivity were measured. The detonation performances were predicted by EXPLO5 and the OB was calculated based on its molecular formula. The results indicate that the self-assembly of PATO and HNO3 effectively enhanced the explosive's OB (−67.7% to −44.6%)and promoted the completeness of the detonation reaction. PATO-N exhibits good thermal stability with an improved decomposition temperature of 315.9 °C. Its theoretical detonation velocity is 7.8 km s−1, while the detonation pressure is 25.2 Gpa. PATO-N exhibited an impact sensitivity (H50) exceeding 112.2 cm, classifying it as an insensitive energetic material.

Comprehensive improvement in the thermal properties, energy characteristics, and hygroscopicity of ammonium perchlorate (AP) carries substantial significance to its utilization in solid propellants. In the present study, a novel coating agent, CuDHT, was synthesized via the self-assembly of 3,6-dihydrazino-1,2,4,5-tetrazine (DHT) and transition metal ions (Cu2+), which can comprehensively enhance the performance of AP. The morphology, composition, and thermal properties of samples prepared in this work were examined via scanning electron microscopy, Fourier transform infrared spectroscopy, powder X-ray diffraction, differential scanning calorimetry, and thermogravimetric analysis techniques. Meanwhile, the burning rate and combustion temperature of AP@CuDHT-based solid propellants were tested via infrared thermography. The findings show that AP particles have their surfaces coated with a homogeneous and compact CuDHT coating layer. Moreover, the CuDHT coating layer is capable of markedly catalyzing AP's thermal decomposition and reducing its hygroscopicity. As the CuDHT coating content increases, the peak temperature of AP@CuDHT's high-temperature decomposition and moisture absorption rate gradually decrease. When the CuDHT content reaches 10 wt %, the HTD peak temperature of AP@CuDHT moves forward by 69.5 °C relative to pure AP, and the moisture absorption rate is cut by 0.326 wt %. Compared with pure AP, AP@CuDHT (10%)'s impact and friction sensitivities are higher by 4% and 8%. Additionally, CuDHT can remarkably enhance the combustion performance of solid propellants. With an increase in CuDHT content, the burning rate of AP@CuDHT-based propellants and their combustion temperature gradually increase. At 10 wt % CuDHT, the burning rate and combustion temperature are enhanced by 6.1 mm·s-1 and 572.6 °C, respectively, compared to those of pure AP-based propellants. In summary, this study provides references for comprehensively improving the hygroscopicity, energy, and thermal properties of AP and, meanwhile, demonstrates a significant application outlook for promoting the combustion performance in solid propellants.

Ionic framework materials have attracted considerable attention in chemistry and materials science. However, their synthesis predominantly relies on the precise selection of ionic components, often requiring a trial-and-error approach. This limitation has significantly impeded the efficient development of such materials. In this study, we propose a robust isomerism strategy that enables the structural transformation from non-framework to framework architectures in ionic systems. F-NH3NH2 and F-NH3OH, the newly developed ionic frameworks, exhibit substantially higher energy and stability than their non-framework isomers, N-NH3NH2 and N-NH3OH. Remarkably, F-NH3OH achieves an exceptional detonation performance, with a velocity of 9442 m/s and a pressure of 38.4 GPa, and mechanical sensitivity, with a friction sensitivity of 120 N and an impact sensitivity of 7 J, rivaling the representative explosive HMX. Single-crystal X-ray diffraction analysis coupled with quantum chemical calculations reveal that the enhanced performance of these ionic framework materials originates from reinforced hydrogen-bonding networks enabled by their complete structural coverage. This work not only provides new insights into the construction of ionic frameworks but also deepens our understanding of how isomerization influences both structure and properties in material science at the molecular level.

ABSTRACT Nickel aminoguanidine perchlorate (NAP) is an energetic coordination compound originally disclosed in a 2010 patent, yet it remains uncharacterized in the peer‐reviewed literature. Despite this, it has attracted attention in informal settings as a potential lead‐free primary explosive. In this study, we present the first comprehensive analytical characterization of NAP, including its synthesis, structure, morphology, vibrational spectra, thermal behavior, and sensitivity. Spectroscopic data (Fourier‐transform infrared, Raman, and ultraviolet‐visible) support coordination of aminoguanidine to a central Ni 2 ⁺ ion, with perchlorate present as a non‐coordinated counterion. Thermal analysis indicates decomposition onset near 270°C. Notably, the mechanical sensitivity of NAP is strongly morphology‐dependent: as‐synthesized needle‐like crystals exhibit high impact sensitivity, while alternative crystallization strategies afford improved handling characteristics. These results provide a necessary foundation for scientific and forensic understanding of a compound that is gaining visibility outside traditional regulatory and research frameworks.