PDF(Pubmed)
Abstract：
The structure and properties of nano-carbon materials formed in explosives detonation are always a challenge, not only for the designing and manufacturing of these materials but also for clearly understanding the detonation performance of explosives. Herein, we study the dynamic evolution process of condensed-phase carbon involved in 2,4,6-Triamino-1,3,5-trinitrobenzene (TATB) detonation using the quantum-based molecular dynamics method. Various carbon structures such as, graphene-like, diamond-like, and \"diaphite\", are obtained under different pressures. The transition from a C sp2- to a sp3-hybrid, driven by the conversion of a hexatomic to a non-hexatomic ring, is detected under high pressure. A tightly bound nucleation mechanism for diamond-like carbon dominated by a graphene-like carbon layer is uncovered. The graphene-like layer is readily constructed at the early stage, which would connect with surrounding carbon atoms or fragments to form the tetrahedral structure, with a high fraction of sp3-hybridized carbon. After that, the deformed carbon layers further coalesce with each other by bonding between carbon atoms within the five-member ring, to form the diamond-like nucleus. The complex \"diaphite\" configuration is detected during the diamond-like carbon nucleation, which illustrates that the nucleation and growth of detonation nano-diamond would accompany the intergrowth of graphene-like layers.
摘要：
炸药起爆过程中形成的纳米碳材料的结构和性能一直是一个挑战,不仅是为了这些材料的设计和制造，也是为了清楚地了解炸药的起爆性能。在这里，我们使用基于量子的分子动力学方法研究了参与2,4,6-三氨基-1,3,5-三硝基苯（TATB）爆炸的凝聚相碳的动态演化过程。各种碳结构，如，类石墨烯，钻石般的，和“双亲”，在不同的压力下获得。从Csp2-到sp3-杂种的过渡，由六原子到非六原子环的转换驱动，在高压下被检测到。揭示了以石墨烯状碳层为主的类金刚石碳的紧密结合成核机制。石墨烯样层很容易在早期阶段构建，与周围的碳原子或碎片连接形成四面体结构，有大量的sp3杂化碳。之后,变形的碳层通过五元环内的碳原子之间的键合进一步彼此聚结，形成钻石状的核.在类金刚石碳形核过程中检测到复杂的“黄体”构型，这说明了爆炸纳米金刚石的成核和生长将伴随着类石墨烯层的共生。
