Preparation and Energetic Properties of Nanothermites Based on Core–Shell Structure

Nanothermites refer to the mixtures of metal fuels and oxidizers, at least one component of which is nanoscale. In the past few decades, nanothermites have attracted much attention as a kind of highly reactive nanoenergetic materials (nEMs). Since nanothermites are mixtures rather than single compounds, the mass-transport efficiency between the reactants dominates their reaction kinetics, thus many efforts have been made to increase the number of contact sites between fuels and oxidizers. Building core–shell structured nanothermites is an effective way to overcome the uneven distribution of fuels and oxidizers and increase the contact area between the reactants. According to the construction sequence of fuel and oxidizer, the core–shell nanothermite can be divided into two main categories, including fuel–oxidizer and oxidizer–fuel. Their exothermic properties, combustion, and pressure performance have been preciously controlled by adjusting composition, size, and structure. In this chapter, the preparation strategies and energetic properties of core–shell nanothermites are introduced and summarized. In particular, the advantages of core–shell structured nanothermites in terms of energy density and combustion efficiency are clarified, based on which suggestions regarding the possible future research directions are proposed.