Crystal morphology prediction of 1,3,3-trinitroazetidine in ethanol solvent by molecular dynamics simulation

Abstract

In order to understand the mechanism of the effect of solvent on the crystal morphology of explosives, and be convenient for the choice of crystallization solvent, the attachment energy (AE) model was performed to predict the growth morphology and the main crystal faces of 1,3,3-trinitroazetidine (TNAZ) in vacuum. The molecular dynamics simulation was applied to investigate the interactions of TNAZ crystal faces and ethanol solvent, and the growth habit of TNAZ in ethanol solvent was predicted using the modified AE model. The results indicate that the morphology of TNAZ crystal in vacuum is dominated by the six faces of [021], [112], [002], [102], [111] and [020], and the crystal shape is similar to polyhedron. In ethanol solvent, The binding strength of ethanol with TNAZ faces changes in the order of [021]>[112]>[002]>[102]>[111]>[020], which causes that [111] and [020] faces disappear and the crystal morphology becomes more regular. The radial distribution function analysis shows that the interactions between solvent and crystal faces mainly consist of coulomb interaction, van der Waals force and hydrogen bonds.

Keywords: 1,3,3-Trinitroazetidine; Crystal morphology; Molecular dynamics simulation; The modified attachment energy model.