In situ preparation of explosive embedded CuO/Al/CL20 nanoenergetic composite with enhanced reactivity

Hybrid explosive-nanothermite energetic composite is synthesized on silicon substrate by embedding hexanitrohexaazaisowurtzitane (CL20) with CuO/Al core/shell nanothermite arrays. The CL20 is in situ integrated with CuO/Al through a facile dissolution-recrystallization process utilizing the core/shell array structure. The hybrid energetic composite is characterized by field-emission scanning electron microscope, X-ray diffraction, and Fourier transform infrared spectroscopy. The heat release characteristics are studied by differential scanning calorimetry and thermogravimetric analysis, and the combustion phenomenon is investigated through open burn experiments. It is found that CL20 is recrystallized within the CuO/Al arrays as a linker with a controllable loading amount. The integration of CL20 explosive not only improves the heat release properties with an increased total heat of reaction and an 18.2% decreased activation energy of integrated CL20, but more interestingly, causes an obvious two-step reaction. Each step is rate-limited by CuO decomposition and diffusion of reacting species through alumina, respectively. In addition, the embedded CL20 and CuO/Al nanothermite arrays jointly ensure a violent and stable combustion behavior, which are very promising for practical applications.