Fabrication of FOX-7 quasi-three-dimensional grids of one-dimensional nanostructures via a spray freeze-drying technique and size-dependence of thermal properties

1,1-Diamino-2,2-dinitroethylene (C₂H₄N₄O₄, FOX-7) quasi-three-dimensional (3D) grids, a promising high-energy-density material with superior sensitivity properties, were synthesized by a spray freeze-drying technique. The FOX-7 3D grids were constructed from one-dimensional nanostructures. The sizes and structures of the FOX-7 3D grids strongly depend on the concentration of the aqueous solution of FOX-7. A possible formation mechanism of this structure was proposed in detail. Thermal analysis reveals that decrease in average particle sizes of FOX-7 grids results in a lower decomposition temperature and a much higher decomposition rate, which is in agreement with those reported about inorganic nanomaterials.