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.
The influence of twinned crystals on the performance of TKX-50 is investigated using normal TKX-50 and twinned TKX-50 supercells. ReaxFF-lg reactive molecular dynamics simulations are performed to study thermal decomposition and oxidation.
In this study, sulfur-free expanded graphite (EG) was obtained by using flake graphite as the raw material, and EG/Fe3O4 composites with excellent microwave absorption properties were prepared by a facile one-pot co-precipitation method. The structure and properties of as-prepared EG/Fe3O4 were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), Raman, X-ray photoelectron spectrometry (XPS), thermogravimetric (TG), and vibrating sample magnetometry (VSM) characterizations. The Fe3O4 intercalated between the layers of expanded graphite forms a sandwich-like structure which is superparamagnetic and porous. When applied as a microwave absorber, the reflection loss (RL) of EG/Fe3O4 reaches −40.39 dB with a thickness of 3.0 mm (10 wt% loading), and the effective absorption bandwidth (EAB < −10 dB) with RL exceeding −10 dB is 4.76–17.66 GHz with the absorber thickness of 1.5–4.0 mm. Considering its non-toxicity, easy operation, low cost, suitability for large-scale industrial production, and excellent microwave absorbing performance, EG/Fe3O4 is expected to be a promising candidate for industrialized electromagnetic absorbing materials.