Confined-Space Self-Assembly of Nano-HNS Into Hierarchical Micro-Nano Structured Microspheres for Selective Stimuli...

To address the balance between reactivity and safety in nano-HNS, this study presents a green composite molding strategy that facilitates the self-assembly of nano-HNS into micro-nano-structured microspheres within confined spaces. This approach utilizes confined spaces to precisely control the morphology and size of the resultant microspheres. The effects of process parameters on the morphology and size of microspheres were systematically investigated, and the underlying formation mechanisms were elucidated. Comprehensive characterizations encompassing morphology, crystal structure, mechanical sensitivity, thermal behavior, and impact properties were conducted. The results demonstrate that the synthesized HNS microspheres possess high sphericity, an average particle size of 224.2 µm, and exhibit favorable fluidity and bulk density. This approach effectively reduces the mechanical sensitivity of the material while preserving the crystal structure and thermal stability of HNS-IV (impact sensitivity: 12 J vs. 20 J; friction sensitivity: 216 N vs. 240 N). Furthermore, it enhances the initial sensitivity to short duration shock, as evidenced by reductions in the 50% and 99.9% initiation voltages by 18 and 48 V, respectively. This approach facilitates the synergistic stimulation of selective sensitization and passivation. This methodology is straightforward and applicable, providing a versatile and eco-friendly approach for the multi-structural modification of nano-HNS.