Elongated conductive structures in detonation soot of high explosives

Abstract

Micrographs of transmission electron microscopy of saved detonation products of benzotrifuroxane at different scales.

Submicrosecond Aggregation during Detonation Synthesis of Nanodiamond

“…Interestingly, the nature and timing of this scattering correspond well with the elongated sp 2 phases and very high conductivities observed in DND-producing explosives that peak at t det ≈ 0.1 μs. 24 Simulations of condensation during detonation have reported the formation of extended carbon networks, 23 somewhat similar to the elongated sp 2 structures observed by TEM. In separate TR-SAXS experiments where the detonation products from the side of the pellet were probed, this characteristic scattering is more clearly observed, as no scattering from the undetonated pellet is present (Figure S10).…”

“…Under these moderate conditions, particle aggregation may proceed by slight differences in the surface charge of the diamond facets, which can be exploited to increase their resistance to aggregation. 22 Unique to high-explosive detonations, DND may condense within an extended network of solid carbon, 23 as evidenced by the very high conductivity observed in the reaction zone of different high explosives, 24 making them especially difficult to isolate both during and after detonation. Although no specific name has been given to the mechanism, for the purpose of discussion here, it will be referred to as condensation−aggregation to denote the almost simultaneous nature of the two events.…”

“…Each of the four explosives investigated here produces a diverse range of particulates, which are observed in postdetonation TEM, with only aggregate structures observed in UFTATB (Figure 2a), comp B (Figure 2b), and octol (Figure S1). The elongated ribbon-like sp 2 structures are abundant in UFTATB 24 and to a lesser extent in comp B (Figure S3) and octol (Figure S2). These phases are expected to contribute to the SAXS more in UFTATB based on prior conductivity experiments 24 and the relative abundance observed by TEM.…”

“…The elongated ribbon-like sp 2 structures are abundant in UFTATB 24 and to a lesser extent in comp B (Figure S3) and octol (Figure S2). These phases are expected to contribute to the SAXS more in UFTATB based on prior conductivity experiments 24 and the relative abundance observed by TEM. Unlike the two DND-producing explosives (comp B and octol), amorphous carbon aggregates can be found in UFTATB and are likely to contribute to the SAXS of UFTATB.…”

“…Because DNTF is known to produce nano-onions, little to no aggregation is expected . UFTATB was chosen for comparison because it condenses a high fraction of elongated sp 2 carbon structures that are also expected to be present to a lesser extent in DND products. , Very little (<1%) DND is found in recovered UFTATB products; therefore, no characteristic scattering from DND is expected.…”