The Safety Properties of a Potential Kind of Novel Green Primary Explosive: Al/Fe₂O₃/RDX Nanocomposite

Quo Vadis, Nanothermite? A Review of Recent Progress

One of the groups of pyrotechnic compositions is thermite compositions, so-called thermites, which consist of an oxidant, usually in the form of a metal oxide or salt, and a free metal, which is the fuel. A characteristic feature of termite combustion reactions, apart from their extremely high exothermicity, is that they proceed, for the most part, in liquid and solid phases. Nanothermites are compositions, which include at least one component whose particles size is on the order of nanometers. The properties of nanothermites, such as high linear burning velocities, high reaction heats, high sensitivity to stimuli, low ignition temperature, ability to create hybrid compositions with other high-energy materials allow for a wide range of applications. Among the applications of nanothermites, one should mention igniters, detonators, microdetonators, micromotors, detectors, elements of detonation chain or elements allowing self-destruction of systems (e.g., microchips). The aim of this work is to discuss the preparation methods, research methods, direction of the future development, eventual challenges or problems and to highlight the applications and emerging novel avenues of use of these compositions.

A Facile Preparation and Energetic Characteristics of the Core/Shell CoFe2O4/Al Nanowires Thermite Film

In this study, CoFe2O4 is selected for the first time to synthesize CoFe2O4/Al nanothermite films via an integration of nano-Al with CoFe2O4 nanowires (NWs), which can be prepared through a facile hydrothermal-annealing route. The resulting nanothermite film demonstrates a homogeneous structure and an intense contact between the Al and CoFe2O4 NWs at the nanoscale. In addition, both thermal analysis and laser ignition test reveal the superb energetic performances of the prepared CoFe2O4/Al NWs nanothermite film. Within different thicknesses of nano-Al for the CoFe2O4/Al NWs nanothermite films investigated here, the maximum heat output has reached as great as 2100 J·g-1 at the optimal thickness of 400 nm for deposited Al. Moreover, the fabrication strategy for CoFe2O4/Al NWs is also easy and suitable for diverse thermite systems based upon other composite metal oxides, such as MnCo2O4 and NiCo2O4. Importantly, this method has the featured advantages of simple operation and compatibility with microsystems, both of which may further facilitate potential applications for functional energetic chips.