Ba(NO₃)₂, as a general oxidizer in the field of pyrotechnics, is known to be too hard to ignite in further application. In this paper, porous Ba(NO₃)₂ was prepared by chemical crystallization to obtain high-sensitivity ignition. The physicochemical properties of the prepared Ba(NO₃)₂ were characterized via scanning electron microscopy (SEM) and X-ray diffraction (XRD), and its thermal properties when mixed with metal oxides were studied via DTA―TG analysis. The SEM image showed that the prepared Ba(NO₃)₂ is a porous structure with poor regularity. XRD results revealed that the crystal form of the prepared Ba(NO₃)₂ did not change intensively. In addition, DTA―TG analysis concluded that the metal oxides affected the decomposition temperature of Ba(NO₃)₂. The initial decomposition temperatures of the mixtures decreased as follows: Ba(NO₃)₂ (582.0 °C) ＞ porous Ba(NO₃)₂ (567.8 °C) ＞ Ba(NO₃)₂ ⁄ NiO (564.2 °C) ＞ porous Ba(NO₃)₂ ⁄ Cu₂O (563.5 °C) ＞ porous Ba(NO₃)₂ ⁄ Fe₂O₃ (556.5 °C) ＞ porous Ba(NO₃)₂ ⁄ CoO (551.6 °C).

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We present a blast wave simulator consisting of a detonation tube and a low-pressure channel with a 25 cm² cross section, which was used to investigate the fluid dynamics of blast injuries. A blast-like flow was generated by detonating a gaseous mixture of ethylene and oxygen with a stoichiometric ratio at or less than the atmospheric pressure. The evolution of the pressure profile at the test section was determined using PZT-type pressure transducers and a high-speedresponse pressure-sensitive paint (PSP), which exhibits optimal linearity in the high-pressure region. Three-dimensional deformation of the test model was examined using sub-millimeter-scale digital image correlation (DIC) to verify the effects of the blast wave and its associated flow. In addition, three-dimensional numerical analysis of the initial detonation was performed to validate the DIC-based experimental result. Together, the experimental and simulated results elucidate the four-dimensional (spatial (x, y, and z) and temporal (t)) effects on the test model. The detonation-driven blast simulator established herein offers the prospect of developing improved protective equipment to combat the risk of blastrelated injuries to the human body.

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We have been developing an ignition system for small satellites that uses energetic ionic liquid propellant (AMU) containing ammonium dinitramide (ADN), monomethylamine nitrate (MMAN), and urea. In this study, we investigated the effect of adding copper compounds to AMU in promoting the exothermic reaction of AMU in the condensed phase and increasing its ignitability by heating. We found that 2 wt% of basic copper nitrate (BCN) can dissolve in AMU. We used differential scanning calorimetry, thermogravimetry-differential thermal analysis, and a digital microscope to observe the condensed-phase reactions of ADN ⁄ BCN, MMAN ⁄ BCN, urea ⁄ BCN, and AMU ⁄ BCN mixtures, and we analyzed the thermal behavior to investigate the influence of BCN on their exothermic reactions. Although BCN dissolved by forming a complex with MMAN, it did not affect the initial exothermic reaction of AMU. BCN promoted the exothermic reaction at high temperatures, and the gross calorific value of the condensed-phase reaction was increased. Hence, adding BCN can potentially improve the ignitability of AMU. The promotion of exothermic reactions was attributed to the decomposition of the copper complex to copper oxide, which promotes the exothermic reaction of MMAN and ammonium nitrate, resulting from the decomposition of ADN.

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Pyrotechnics, which include magnesium powder, produce bright flames, but magnesium is easily aged by water. To prevent the aging problem, which decreases the burning performance and increases the risk of spontaneous combustion, it is necessary to use a stabiliser. In this study, we observed the stabilisation effect of surfactants on the aging of magnesium with ammonium perchlorate and water. The effect of sodium stearate, a straight-chain carboxylate, on the aging of magnesium with ammonium perchlorate and water, was analysed. The results showed an increase in the apparent activation energy of the exothermic reaction of magnesium when sodium stearate was used as a stabiliser. Furthermore, our experiments revealed the stabilising capability of sodium laurate, sodium behenate, and sodium dodecylbenzenesulfonate. But sodium propionate did not exhibit a pronounced stabilisation capability. The experimental results revealed that the stabilisation effect of straight-chain carboxylates increased with increasing length of their hydrocarbon chains. The relationship between the stabilisation effect and the hydrophilic-lipophilic balance was evaluated and revealed that the stabilisation effect of the surfactant on the aging of magnesium with ammonium perchlorate and water depends on its hydrophilicity.

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