Effect of zinc doping on pentaerythritol tetranitrate single crystals

Abstract

In this study, the effect of zinc impurity on the organic high explosive pentaerythritol tetranitrate (PETN) single crystal has been investigated with optical microscopy and ex situ atomic force microscopy (AFM). The optical images show that the crystal shape has a transition with a predictable trend from long crystal to compact one as the zinc concentration is increased. Also, the 2-dimentional (2-D) growth hillocks are observed clearly on (110) face with contact AFM. The crystal growth occurs on monomolecular steps generated by 2-D nucleation and followed by layer-by-layer expansion, and the macro-steps formed onto the surface before spreading laterally as step bunches. The zinc ions are incorporated in growth steps as the zinc concentration is increased. The mechanism of inorganic impurity on molecular crystallization growth is still unclear. However, the incorporation of impurities may significantly affect growth kinetics of defect structure, and the bulk properties of molecular crystals.

Surface Studies of β-1,3,5,7-Tetranitro-1,3,5,7-Tetrazoctane and Pentaerythritol Tetranitrate from Density Functional Tight-Binding Calculations and Implications on Crystal Shape

“… a The planes are sorted with respect to their surface energies, and those observed experimentally for β-HMX − and PETN ,,− are highlighted in bold . …”

“…(b) is reprinted from ref , Copyright (2007), with permission from Springer Nature. (c) is reprinted from ref , Copyright (2010), and (e) is reprinted from ref , Copyright (2016), with permissions from John Wiley & Sons.…”

“…With the exception of the marginal appearance of (100), (010), (111), (111̄),(1̄11), and (1̄11̄) in the SE model, all experimental planes are prominently captured in the predictions. Crystals in (a), (b), (c), (e), and (g) are formed in acetone solvent at low temperatures (∼4 °C for (a), (e), and ∼25 °C for (b), (c), (g)), and the one in (d) is formed in ethyl acetate at ∼25 °C. ,− , The elongation in (f) is attributed to nonequilibrium growth kinetics resulting from the aging of PETN crystals at elevated temperature (∼80 °C) for 90 days . However, the reasons for elongation in (e) and (g) are difficult to articulate based on the provided conditions.…”

Molecular dynamics study on the effect of metal ion doping on the performance of HMX

“…Existing studies have shown that metal ions, as trace impurities, can change the crystal morphology, growth rate, and internal defects of explosives, thereby affecting their stability and, in particular, their thermal properties. [10][11][12] Xu et al 13 analyzed the influence of metal ion impurities on the crystallization and thermal properties of HMX and found that different types of metal ions have significant effects on the safety of explosives. Pitchimani et al 14 studied the morphology and activation energy of pure PETN crystals and PETN crystals doped with metal ion impurities.…”