A promising strategy to obtain high energy output and combustion properties by self-activation of nano-Al

Aluminum based energetic nanomaterials attract significant attention for various applications owing to their ultrahigh energy density . The main obstacle in the application of nano-Al based energetic materials is the slow combustion reaction kinetics and reduced energy output resulting from the inert Al 2 O 3 shell. In this paper, an efficient surface self-activation strategy is proposed to significantly improve the combustion performance and energy output of nano-Al based energetic materials. A porous AlF 3 shell is formed on the surface of the nano-Al particle by an etching reaction between perfluorododecanoic acid and the Al 2 O 3 dense layer. The porous AlF 3 shell provides a new reaction channel for the reaction of Al and the oxidizer , thus significantly improving the energy output and combustion reaction kinetics. The energy output and combustion reaction speed of polytetrafluoroethylene (PTFE)/nano-Al coated with C 11 F 23 COOH are 6304 J/g and 670 m/s, which are 3.0 and 2.6 times higher than those of PTFE/nano-Al, respectively. The mechanism of the self-activating process is proposed to explain the enhanced combustion reaction kinetics and energy output of the nano-Al based energetic materials. The proposed surface self-activation strategy for nano-Al particles can efficiently to enhance the reactivity and energy output and promote the development of the nano-Al based energetic materials.