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

Abstract

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 °C) was increased by 45 °C and had a faster energy releasing efficiency and released more energy compared to original and sub-micro particle crystals (222.7 °C). There is a potential alternative application for micro-electromechanical systems (MEMS), micro thrusters and so on.