Entropy-mediated solidification stabilizes and enhances energetic release in amorphous energetic materials
摘要
The formation of stable amorphous phases in rigid organic small molecules is fundamentally hindered by their pronounced crystallization tendency. This challenge is particularly acute in energetic materials, in which the amorphous phase must be stabilized without inert additives to preserve high energy density. Here, we overcome this longstanding obstacle by realising a stable amorphous energetic material based on the small molecule explosive (4,4′,5,5′-tetranitro-1H,1′H-2,2′-biimidazole-1,1′-diamine, DATNBI). The amorphous DATNBI (AEM-DATNBI) prepared via a melt quenching process, exhibits a glass transition temperature of 59.67 °C and demonstrates remarkable structural stability below this threshold, maintaining its integrity for over 24 hours at 60 °C. This stability originates from a synergistic interaction between the non-planar molecular framework and a three-dimensional hydrogen-bond network formed by -NH₂/-NO₂ groups. This unique amorphous structure not only enhances safety by suppressing hotspot formation but also accelerates energy release, leading to faster combustion and more complete decomposition. This study demonstrates a general strategy leveraging steric hindrance and intermolecular interactions, thereby extending the realm of amorphous materials to energetic compounds and other functional rigid organic small molecules.