Formulation and Characterizations of Nanoenergetic Compositions with Improved Safety

In order to improve the safety of energetic compositions, whether it has to be worked with less sensitive materials that are often less powerful or with high energetic materials crystals with improved purity and microstructure quality. A way to modify the crystal quality of an energetic material is to structure the matter on the nanoscale: the crystals size reduction should induce impurity modifications in the particles. That is one of the reasons why interest in nanoenergetic compositions that contain high energetic material (>= 90 wt-%) and an organic matrix (<= 10 wt-%) that takes part in constraining the explosive to organize itself on the nanoscale arose. The key point is to find or synthesize the matrix. In the course of this study, first ammonium perchlorate compositions structured on the nanoscale were synthesized (150 nm AP particles (80 wt-%) dispersed in an organogel matrix (20 wt-%)). The formulation process was based on the impregnation of porous organogels with a saturated aqueous solution of ammonium perchlorate followed by freeze drying. The overall composition had an oxygen balance equilibrated towards CO2. These AP nanocompositions show better safety behavior during combustion than there equivalent macrocompositions, while they burn more rapidly, with no degradation of their impact and thermal sensitivity properties. The formulation process of RDX nanocompositions is more complex as the solvent used is gamma-butyrolactone which can not be directly frozen dried. However, first RDX nanocompositions were formulated and characterized using differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X-ray powder diffraction, and drop weight impact. Lately compressions of these RDX compositions were performed, prior to gap-test experiments.