Microcrystalline PETN Prepared Using Microfluidic Recrystallization Platform and Its Performance Characterization

Abstract

AbstractThe particle size of explosives plays a key role in the short‐duration pulse shock initiation, and explosives with small grain size and large specific surface area (SSA) generally have preferable sensitivity properties. We have constructed a high‐throughput microfluidic recrystallization platform, aiming to prepare ultrafine pentaerythritol tetranitrate (PETN, C(CH2NO3)4) via a precisely controllable solvent/nonsolvent recrystallization process. Through this platform, the recrystallized PETN was produced with a particle size of about 2 μm, and its SSA was above 70‐fold that of the raw PETN. The X‐ray diffraction results indicated that the raw and microcrystalline PETN had a similar diffraction spectrum. The thermal analysis demonstrated that compared with the raw PETN, the microcrystalline PETN revealed better decomposition performances. Importantly, the short‐duration pulse shock initiation sensitivity of microcrystalline PETN pellets was evaluated when subjected to an exploding foil initiator. The shock initiation threshold results were as follows: 50 % initiation voltage U (50 %)=1332 V, the corresponding capacitor storage energy was 195.2 mJ. Furthermore, the calculated shock pressure and shock duration imparting to the pellets were 9.61 GPa and 12.53 ns respectively, corresponding to the 3162 m/s threshold velocity. Finally, the enhanced sensitivity during the shock‐to‐detonation transition was further explained with the hot spot‐based mechanism.