Facile formation of nitrocellulose-coated Al/Bi2O3 nanothermites with excellent energy output and improved electrostatic discharge safety

Publication date: 5 April 2018
Source:Materials & Design, Volume 143
Author(s): Ji Dai, Jianbing Xu, Fei Wang, Yu Tai, Yun Shen, Ruiqi Shen, Yinghua Ye
Nanothermites are attracting much attention for energetic applications. However, they suffer from high electrostatic discharge (ESD) sensitivity which makes their handling hazardous. Developing safe yet powerful nanothermites is still a challenge. In this work, nitrocellulose (NC) was adhered to the surface of Al and Bi2O3 nanoparticles by a facile electrospray method aiming to improve the ESD safety and energy output of Al/Bi2O3. The morphological and compositional characterization of Al/Bi2O3@NC confirms the NC-coated structure. Benefiting from the structure, the ESD safety of coated Al/Bi2O3 is improved, for instance, the Al/Bi2O3@NC containing 10wt% of NC has a ESD ignition threshold to be 81mJ instead of 1mJ for the Al/Bi2O3 without NC. On the other hand, tunable energy output is obtained by the addition of NC coating. Specifically, Al/Bi2O3@NC (3wt%) exhibits remarkably enhancements in pressurization, combustion reaction and heat release, which even outperforms the most widely used primary explosive lead styphnate (LTNR). The enhancements are attributed to the fact that NC serves as a gas-generating agent to prevent the nanoparticles from sintering to larger particles and enables sufficient combustion. These results suggest that the electrospray formation of NC-coated nanothermites is a facile strategy for obtaining novel nanothermites.

Graphical abstract

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