2022-08-01 ローレンスリバモア国立研究所(LLNL)
研究チームは、原子レベルで分解された大規模な反応性分子動力学スーパーコンピュータシミュレーションを用いて、ホットスポットがどのように形成・成長するかを直接計算し、何が原因で反応するのかをより深く理解することを目指した。
この研究は、変形した分子のメカノケミストリーが、ホットスポットや、せん断帯のような塑性変形の他の領域での反応を加速させる役割を担っているという明確な証拠を提供しています。
＜関連情報＞
- https://www.llnl.gov/news/research-finds-mechanically-driven-chemistry-accelerates-reactions-explosives
- https://pubs.acs.org/doi/10.1021/acs.jpclett.2c01798
即興メカノケミストリー：分子内歪みエネルギーによる衝撃波誘起超高速化学反応Extemporaneous Mechanochemistry: Shock-Wave-Induced Ultrafast Chemical Reactions Due to Intramolecular Strain Energy
Brenden W. Hamilton, Matthew P. Kroonblawd, and Alejandro Strachan
Journal of Physical Chemistry Letters Published:July 15, 2022
DOI:https://doi.org/10.1021/acs.jpclett.2c01798
Abstract
Regions of energy localization referred to as hotspots are known to govern shock initiation and the run-to-detonation in energetic materials. Mounting computational evidence points to accelerated chemistry in hotspots from large intramolecular strains induced via the interactions between the shock wave and microstructure. However, definite evidence mapping intramolecular strain to accelerated or altered chemical reactions has so far been elusive. From a large-scale reactive molecular dynamics simulation of the energetic material 1,3,5-triamino-2,4,6-trinitrobenzene, we map decomposition kinetics to molecular temperature and intramolecular strain energy prior to reaction. Both temperature and intramolecular strain are shown to accelerate chemical kinetics. A detailed analysis of the atomistic trajectory shows that intramolecular strain can induce a mechanochemical alteration of decomposition mechanisms. The results in this paper could inform continuum-level chemistry models to account for a wide range of mechanochemical effects.
