Preparation and characterization of nano-1,1-diamino-2,2-dinitroethene (FOX-7) explosive

Nano-1,1-diamino-2,2-dinitroethene (FOX-7) explosive particles were successfully prepared via an ultrasonic spray-assisted electrostatic adsorption (USEA) method and sub-micro FOX-7 was also obtained by recrystallization (using absolute ethyl alcohol as the solvent) for comparison. The samples were characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM) and particle size and size distribution. The results showed that there were two groups of size distribution. For the nano-sized FOX-7, prepared by the USEA method, the size distribution was in the range of 30 to 200 nm and the average particle size of FOX-7 was approximately 78 nm. While, sub-micro FOX-7 particles obtained via recrystallization had a single size distribution of 200-450 nm. The particles were cubic and spheroidal, respectively. What's more, their thermal properties were also investigated by differential scanning calorimetry (DSC) and thermogravimetry (TG). For nano-sized FOX-7, the first exothermic peak (267.4 degrees C) was increased by 45 degrees C and had a faster energy releasing efficiency and released more energy compared to original and sub-micro particle crystals (222.7 degrees C). There is a potential alternative application for micro-electromechanical systems (MEMS), micro thrusters and so on.