Nanostructured Energetic Composites: Synthesis, Ignition/Combustion Modeling, and Applications

Abstract

Nanotechnology has stimulated revolutionary advances in many scientific and industrial fields, particularly in energetic materials. Powder mixing is the simplest and most traditional method to prepare nanoenergetic composites, and preliminary findings have shown that these composites perform more effectively than their micro-or macro-sized counterparts in terms of energy release, ignition, and combustion. Powder mixing technology represents only the minimum capability of nanotechnology to boost the development of energetic material research, and it has intrinsic limitations, namely, random distribution of fuel and oxidizer particles, inevitable fuel pre-oxidation, and non-intimate contact between reactants. As an alternative, nanostructured energetic composites can be prepared through a delicately designed process. These composites outperform powder-mixed nanocomposites in numerous ways; therefore, we comprehensively discuss the preparation strategies adopted for nanostructured energetic composites and the research achievements thus far in this review. The latest ignition and reaction models are briefly introduced. Finally, the broad promising applications of nanostructured energetic composites are highlighted.

Enhanced energy performance from core–shell structured Al@Fe2O3 nanothermite fabricated by atomic layer deposition

“…By alternately exposing the substrate to the metal source and the oxygen source, metal oxide lms can be grown layer by layer. 27,28 So far ALD has been utilized to deposit many metal oxides that can be used for thermite reactions, including Fe 2 35 Ferguson et al 36 rst employed ALD to deposit SnO 2 coatings on nanoparticles of Al. However, due to insufficient reactant exposures, the ALD surface reaction was not saturated, leading to limited lm growth and large deviations from the expected oxidizer to fuel (O/F) ratio.…”

“…Combustion processes were also recorded by a digital video camera at 30 fps. Among these precursor combinations, the most ubiquitous recipe currently used for depositing iron oxide by ALD involves the use of Fe(Cp) 2 and oxygen. As an ALD precursor Fe(Cp) 2 is attractive as it is commercially available, remarkably inexpensive, and has high thermal stability (above 500 C) in the gas phase.…”

“…In the temperature range of 350-500 C the reported Fe 2 O 3 lm growth rate is 0.06-0.14 nm per cycle on at or porous substrates. 29,48 In this work Fe(Cp) 2 and O 2 are used as precursors for Fe 2 O 3 ALD. ALD reactions were carried out at 350 C because this temperature has been proved to be mild enough for processing thermite materials.…”

Preparation and Evaluation of Hybrid Composites of Chemical Fuel and Multi-walled Carbon Nanotubes in the Study of Thermopower Waves

“…1 In particular, many researchers have endeavored to use chemical fuels as the energy source for nextgeneration micro/nanosystems-based technologies. 2 However, owing to the difficulty in integrating energy conversion components in extremely small spaces in micro/nanodevices, there are fundamental limitations to the conversion of chemical fuels into electrical energy.…”

“…Therefore, the combustion of chemical fuels has mainly been employed for the production of chemical or mechanical energy in micro/nanodevices such as nanothermites or microactuators. 1,3 Thermopower waves-a newly developed energy conversion concept-have attracted considerable attention as a method for converting the chemical energy of a fuel directly to electrical energy without using any converting components. 4,5 Thermopower waves can be generated using a hybrid composite of a chemical fuel and a micro/nanostructured material.…”