Molecular Dynamics Simulation of CL-20/DNDAP Cocrystal Morphology at Different Temperatures

The cocrystallization of hexanitrohexaazoisowuzane (CL-20) with other energetic materials alongside the sphe-roidization of cocrystal morphology can reduce its sensitivity.The attachment energy (AE) model and molecular dynamics (MD) method were used to predict the morphologies of CL-20 and 2,4-dinitro-2,4-diazapentane (DNDAP) cocrystal in methyl acetate solvent at different temperatures.Meanwhile, the interaction energy between the solvent and the crystal surface was calculated to derive the attachment energy of the crystal surface, and the crystal morphologies at different temperatures were simulated.The results show that there are five morphologically dominant crystal faces of CL-20/DNDAP cocrystal under vacuum.The (10 0) face occupies a relative large area accounting for 37.44% , which has a significant influence on the crystal morphology.The attachment energy of CL-20/DNDAP cocrystal decreases with the increasing of temperature.The higher temperature leads to an increase in the aspect ratios, which are 1.80 and 3.93 at 280 and 360K, respectively.The lower temperature is beneficial to obtain a nearly spherical morphology.The theoretical predicted morphology of tilted prisms agrees with the experimental result. © 2023 China Ordnance Industry Corporation. All rights reserved.