Effect of nanostructures on the exothermic reaction and ignition of Al/CuOx based energetic materials

Al/CuOx based micro- and nanoenergetic materials (EMs) have been made by the thermal oxidation of Cu thin films deposited onto silicon substrates followed by Al integration through thermal evaporation. The micro- and nano-EMs are then characterized by scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction, differential thermal analysis, and differential scanning calorimetry. By comparing the thermite reactions and ignition properties of Al with micro-CuOx and Al with nano-CuOx, we show experimentally that one-dimensional nanostructures (CuO nanowires) and nano-Al affect greatly the exothermic behaviors and ignition properties of the Al/CuOx based EMs. The higher surface energy associated with the CuO nanowires and the deposited nano-Al is believed to be a possible factor contributing to the enhanced exothermic reactions that occur below the melting point of Al and the smaller ignition delay and lower ignition energy.