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Terahertz (THz) spectra of two TNT-related compounds (4-NT and 2, 6-DNT) are investigated using Fourier transform infrared spectroscopy (FTIR, 1.5-20 THz) and THz time-domain spectroscopy (THz-TDS, 0.2-2.5 THz). Density functional theory (DFT) is applied to calculate THz spectra of these two compounds. Transmission, diffuse reflection, and calculated spectra are in good agreement. The measured THz resonance lines from the transmission and diffuse reflectance spectra are assigned based on the DFT simulation. The observed THz signatures imply that THz spectrum has potential for standoff detection of explosives and related compounds (ERCs) in the THz range.

The detonation of carbon- or nitrogen-containing explosives not only produces powerful shock waves but also provides elemental building blocks and a unique high-pressure and high-temperature physical environment for the construction of various nanostructures. This review highlights the situation and key progresses in the detonation approach towards diamond nanoparticles, graphitic carbon nanotubes, fullerene molecules, and gallium nitride nanocrystals. Further extension of the peaceful-use detonation applications and rational reactor design are also proposed.

Real time detection of explosive residues is important to mitigate increasing security threats. Therefore, systematic studies are essential to optimize the performance of sensors. In this work, we have explored β-octamethoxyporphyrin and β-octabutoxyporphyrin to evaluate the effect of alkoxy groups in solution and in vapor phase sensing of nitrated explosives. Our systematic studies revealed a marked difference in sensitivity of these free-base porphyrins in solution state and vapor phase sensing of nitrated explosives simply by modulation of alkyl chain lengths. Alkoxyporphyrins exhibit very good sensitivity towards not only nitro aromatics but also alkyl nitro explosive taggants compared to β-octaethylporphyrin. Therefore, alkoxyporphyrins may act as versatile fluorescence turn-off based chemical sensors for nitrated explosives.

Terahertz (THz) spectra of two TNT-related compounds (4-NT and 2, 6-DNT) are investigated using Fourier transform infrared spectroscopy (FTIR, 1.5-20 THz) and THz time-domain spectroscopy (THz-TDS, 0.2-2.5 THz). Density functional theory (DFT) is applied to calculate THz spectra of these two compounds. Transmission, diffuse reflection, and calculated spectra are in good agreement. The measured THz resonance lines from the transmission and diffuse reflectance spectra are assigned based on the DFT simulation. The observed THz signatures imply that THz spectrum has potential for standoff detection of explosives and related compounds (ERCs) in the THz range.