Energetic nanoarray structures by confined crystallization for enhanced energy-release efficiency

Abstract

For energetic materials (EMs), the crystal morphology, particle size and surface state have significant effects on their properties. Nano-sized EMs have attracted considerable research interests during the past decades because of their improved performances in ignition, combustion, and energy-release rate. In this work, several novel nanoarray-structured EMs have been prepared by a facile freeze-drying confined crystallization method, which is based on the self-assembly of materials during rapid recrystallization. The effects of reaction conditions on the morphology and structure of these EMs have been comprehensively studied using state-of-the-art techniques. Thermal decomposition kinetics was obtained from DSC data by Kissinger method. The mechanical sensitivity, ignition and combustion in a chamber with fixed volume were conducted. Such energetic crystal nanoarrays show typical one-dimensional morphology, with long aspect ratio and large specific surface area, some of which also have a distinctive fractal structure. Sensitivity results confirmed the visibly reduced impact and friction sensitivity of the energetic nanoarrays. Compared with normal energetic crystals, these as-prepared nanoarrays exhibited lower onset thermal decomposition temperature, higher ignition efficiency, and better combustion performance, particularly for the nanoarray of two-component composites containing both fuel and oxidizer.