Novel method for the preparation of explosives nanoparticles

Abstract

We report the preparation of explosives nanoparticles of RDX and TNT in a variety of substrates that include glass, silicon and stainless steel. The explosive nanoparticles were prepared by means of pneumatically assisted nebulization (PAN) using an electrospray (ESI) needle, which allowed for the direct deposit of the energetic material onto the substrate. The deposited nanoparticles were characterized by optical microscopy, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray analysis (EDX) and Raman Microscopy. SEM micrographs showed that the process produced particles with a mean size in the range of 80 -500 nm and a narrow size distribution. For TNT, the process produced smaller particles with a narrower size distribution. The EDX spectrum showed the presence of carbon, nitrogen and oxygen consistent with the elemental composition of the energetic materials. The chemical properties of the nanoparticles were also determined by vibrational spectroscopy.

Optical Properties of β-RDX Thin Films Deposited on Gold and Stainless Steel Substrates Calculated from Reflection–Absorption Infrared Spectra

“…Thin film deposition by spin coating offers considerable advantages compared with methods such as sample smearing, 26 drop casting, 44 air spraying, 45 pneumatically assisted nebulization, 46 etc. This is because it is less subject to human error and provides a reliable coated surface for optical property studies.…”

Developments and challenges in the manufacturing, characterization and scale-up of energetic nanomaterials – A review

“…solid particles are generated by first forming small solution droplets containing the material to be crystallized and subsequent evaporation of the solvent leading to nucleation and growth of the dissolved material. Spray drying [7], electrospray [10] and spray flash evaporation [11] depend on this principle. A (under)saturated solution is sprayed over a nozzle generating many small, practically monodisperse droplets.…”

“…Finally, once all solvent has evaporated, the nanoparticles can be collected on a surface. Barreto-Cabán et al [7] used a spray drying technique to prepare RDX and TNT nanoparticles, starting from a solution in methanol, on a silicon substrate. In this way RDX with a mean size of 250-500 nm and a narrow size distribution could be produced.…”

“…Crystallographic information and identification of the existence of different polymorphs or cocrystals can be obtained using X-ray diffraction (XRD) [7,19]. Identification can be achieved by means of spectroscopic techniques like FT-IR [22,57] and Raman [7]. Using DSC and TG/DTA the endo-and exothermal properties like polymorphic phase transitions, melting and decomposition can be determined [57].…”

“…The size of an inclusion is typically a few micron and larger. The prospect that the number of defects in nanoparticles can be reduced considerably compared to conventionally sized energetic materials, has been an important driver for the research and development on energetic nanomaterials since this is expected to lead to less sensitive energetic materials [6][7][8][9][10][11][12].…”