| Summary: | 碩士 === 國防大學中正理工學院 === 應用化學研究所 === 89 === The objective of this study is to simulate the dynamic crystal morphology of HNIW and ONC, the advanced high-energy explosives. The molecular simulations were using the UFF, the Dreiding and the Compass molecular forces fields, respectively, associated with BFDH and attachment habit theories. The computational results of the attachment and the slice energies of the crystal main faces have shown that the ε-HNIW explosive has less attachment energies and much easier to explode so that it can be used as the warhead's main charge for military purposes. The predictions of the slice energies have concluded that the thermal stability of the ONC explosive is higher than that of the HNIW explosive. The packing density of the ONC explosive is 2111 kg/m3, which was estimated using the Compass molecular force field and was the highest value among the synthesized explosives.
The Monte Carlo method was applied to simulate the molecular self-adsorption of the RDXs and the results showed that the explosive molecules have higher adsorption energies than the solvent. The MDI, usually as a binder, has a higher adsorption energy onto the HMX explosive than onto the HNIWs. Furthermore, the α-HNIW and the γ-HNIW molecules in the xylene solvent were adsorbed onto the α-HNIW or onto the γ-HNIW molecules according to the crystal morphology of the HNIWs. The adsorption energies of this self-adsorption system were obtained for different conformational structures of HNIW molecules. We hope that the morphology transfer phenomena and the mechanism between conformational structures of high-energy explosives can be well understood and explained so that one can controlled the transfer processing of the explosive manufacture for the sake of industrial safety. In addition, the molecular dynamic simulations were performed to compute the volume expansion coefficients of the ε-HNIW under vacuum. The computations of volume expansion coefficients help us understanding the thermal stability of high-energy explosives under the abominable operating environment.
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