Desensitization of spherical CL-20 composites by embedding insensitive nanosized energetic crystals†

Abstract

The development of spherical CL-20-based co-particles, which incorporate nanosized nLLM-105@PDA and nFOX-7@PDA crystals at different ratios (1%, 5%, and 10%), has been achieved using a spray drying technique. This innovative approach results in solid spherical co-particles where the nanosized inclusions are tightly integrated in CL-20 based composite crystals, where the outer shell is primarily composed of CL-20. Scanning electron microscopy (SEM) confirms the structural integrity of these co-particles, and nano-computed tomography further elucidates the intricate interfacial structure. Differential scanning calorimetry (DSC) and thermogravimetric (TG) analyses reveal that these co-particles undergo a single-step decomposition process, akin to their energetic co-crystals. This behavior is indicative of a unified and predictable thermal response. Molecular dynamics (MD) simulations, employing a reactive forcefield, have been conducted to track their thermal decomposition products. Although the CL-20 polymorph in both co-LLM-105_P/CL-20 and co-LLM-105_P/CL-20 co-particles is in the β-phase, their impact initiation energy is approximately 4 to 6 times higher than that of raw ε-CL-20. Moreover, the co-particle formulation does not adversely affect the velocity of detonation (VoD) and detonation pressure (P_C–J), showing that the energy density is preserved.