Size-dependent shock response mechanisms in stacked nanoparticles of 1,3,5-triamino-2,4,6-trinitrobenzene

Abstract

Controlling the particle size of energetic materials is an effective strategy for balancing sensitivity and energy performance. Achieving this balance requires a thorough comprehension of how size-induced structural transformations influence response mechanisms, especially under shock loading. Herein, we study the effects of particle size on the shock response of stacked TATB nanoparticles using non-reactive molecular dynamics simulations. The results show that configurations with smaller nanoparticles exhibit minute voids and maintain ordered molecular layers within the particles. These structural features collectively delay the average temperature rise during shock loading, primarily due to two factors. First, the collapse of minute voids generates localized hot spots with relatively low temperatures. Second, the ordered layer arrangement raises the threshold for densification strain, effectively hindering the formation of rapidly developing high-temperature bands. Additionally, at an elevated initial temperature, the structural layers become disordered and voids are largely eliminated, resulting in reduced energy localization and diminished size-dependent responses under shock loading. Overall, this study reveals the size-dependent response mechanisms at the nanoscale and provides valuable insights into the design, optimization, and storage of the TATB-based energetic materials.