Herein, the attachment energy (AE) model was employed to study the growth morphology of 3,4-bis(3-nitrofurazan-4-yl)furoxan (DNTF) under vacuum and solvent conditions by molecular dynamics simulation. The DNTF crystals were cultivated in H2O/acetic acid (AcOH) and H2O/EtOH solvents by natural cooling. The calculated results show that the (0 1 1) and (0 0 1) faces have large morphological importance in these two solvent systems, and the predicted DNTF morphologies agree qualitatively with those of the observed experimental results. Radial distribution function (RDF) and diffusion coefficient analyses were performed to explore the adsorption and diffusion behaviors of solvent molecules on DNTF surfaces. Furthermore, the impact and friction sensitivities of different crystal morphologies of DNTF were also tested and discussed. Results suggest that crystal morphology is an important impact factor for controlling the sensitivity of explosives.

Crystal morphology of 3,4-bis(3-nitrofurazan-4-yl)furoxan (DNTF) in a solvent system: molecular dynamics simulation and sensitivity study

In this work, molecular dynamics simulations have been performed to study the solvent effect on the crystal morphology of hexogen. The hexogen growth habits in a vacuum predicted by the AE model are dominated by the (111), (020), (200), (002), and (210) faces. Hexogen surfaces–acetone solvent micro interface models are constructed to study the adsorption behavior of acetone on these habit planes. The modified attachment energy model considering both the solvent–surface adsorption interactions and surface structures is proposed to predict the crystal morphology of hexogen in the acetone solvent. The calculations of the modified attachment energies suggest that via the effect of acetone solvent, the (210) face has the largest morphology importance and the morphological importance of the (111), (002) and (200) faces reduces, whereas the (020) face disappears. The predicted result is in reasonable agreement with the observed experiment shape. Furthermore, the diffusion coefficients of acetone solvent toward the different RDX surfaces suggests that the (210) and (111) faces are the dominate growth faces on the final RDX crystal habits, whereas the (020) face probably disappears, which validates the reliability of the modified attachment energy model.

A study of the solvent effect on the crystal morphology of hexogen by means of molecular dynamics simulations

The crystal morphology of the energetic material cyclotrimethylene trinitramine (also known as RDX) influenced by the solvent effect was investigated via molecular dynamics simulation. The modified attachment energy (MAE) model was established by incorporating the growth parameter-solvent term. The adsorption interface models were used to study the adsorption interactions between solvent and RDX surfaces. The RDX crystal morphology grown from the cyclohexanone (CYC) solvent as a case investigation was calculated by the MAE model. The calculation results indicated that, due to the effect of CYC solvent, (210) and (111) faces had the greatest morphological importance on the final RDX crystal, while the morphological importance of (020), (002), and (200) faces were reduced. The predicted RDX morphology was in reasonable agreement with the observed experiment result.

Prediction of crystal morphology of cyclotrimethylene trinitramine in the solvent medium by computer simulation: a case of cyclohexanone solvent.

Growth and morphology of 1,3,5,7-tetranitro-1,3,5,7-tetraazacy-clooct ane (HMX) crystal

The vacuum, water-effect and ethanol-effect morphology of 3-nitro-1,2,4-triazole-5-one (NTO) is simulated using the attachment energy model by the molecular dynamics (MD) simulation method. The model size of the boundary layer dramatically influences the time and accuracy of the simulation. To study the crystal habit of NTO in a solvent within a short time and with high accuracy, the model size is first discussed. As the outcomes of NTO in water and ethanol are unsatisfactory, we propose the study of morphology control, which is performed by adding water to ethanol to adjust the growth rate of NTO surfaces. Based on the growth rate of each surface, we obtain a suitable mass ratio of ethanol/water, in which NTO is recrystallized and the crystal morphology is ameliorated. Besides, the radial distribution function (RDF) analysis shows that the solvent molecule adsorption on NTO molecules is mainly via solvent-crystal face interactions of hydrogen bonding. The simulation results can provide some guidance for the crystallization process of NTO, and the model size can also be applied in the morphology control of other compounds.

Morphology control of 3-nitro-1,2,4-triazole-5-one (NTO) by molecular dynamics simulation

In this work, a molecular dynamics investigation was performed to study the effect of the solvents acetone and cyclohexanone on the crystal habits of hexogen. The results show that the adsorption e...

XIAMing-zhu

Papers

Molecular dynamics investigation of the effect of solvent adsorption on crystal habits of hexogen