Opportunities in Engineering Energetic Materials

When Michael Faraday introduced his famous lectures on candles, he the topic with: “There is no better, there more open door by which you can enter into study of natural philosophy than considering physical phenomena a candle.” 1 This even true in energetic materials that arguably multidisciplinary, including chemistry, physics, fluid mechanics, heat transfer, and material science, addition function at extremes pressure, temperature, time scale. Amazingly, are nearly endless possibilities for novel stimulate all other areas this exciting research area. we consider advanced propellants, explosives, pyrotechnics almost exclusively think new molecules – polymeric or crystalline. includes cocrystals two where improved be developed using existing molecules. However, least as much opportunity improvement through modifying microscopic macroscopic structures components. We could call approach engineering materials. These engineered designed offer significant benefits performance, sensitivity, life cycle issues. Approaches include additive manufacturing, mechanical activation (MA) (or arrested ball milling, ABM), coatings (including core-shell particles), surface modification, composite particles. Both top-down bottom-up fabrication methodologies yield important systems. Most current composites composed crystalline, often metal particles, with polymers (binders) mixed then cast place pressed machined to final shape. Formulators choose used (composition) size distributions, but conventionally do not precisely control microstructure engineer particles used. Additive manufacturing (AM) opening capability microstructures beyond casting machining. lead previously unobtainable enable functional gradation controlled integration multiple For propellants pathway tailored grains precise grain geometry, materials, prescribed deflagration propagation 2. Likewise, detonation wave shaping may possible achieve better corner turning desired effects on-demand sensitivity explosives 3. has potential impact too 4, 5. Improved igniters 6, flares, reactive structures, smart multifunctional 7 just few pursued. A AM also exists replacing inert printed complex ones increases overall system performance. There lot development required its full potential. Complementing effort, particle offers opportunities entirely applications. Some liquid fuels miscible mixtures, forming homogeneous mixture, others emulsions microscopically heterogeneous; metals crystalline analogies 8. example, alloys solid phase mixtures heterogeneous. numerous these types have microstructure: imagined example. Coatings treatments 9, geometries, foils (layered materials) 10, MA/ABM, alloys, multicomponent crystals (not well-ordered co-crystals amorphous multicomponent-crystals) additional approaches. ignition thresholds dramatically decreased, reactions rates increased some cases 11. Furthermore, when disparate volatilities components either (e. g., alloys) heterogeneous (composite particles) metals, microexplosions occur improve combustion efficiency decrease two-phase flow losses 12. Using such create many yet Consider core might very surrounded shell compatible polymers. In short, unique disruptive work remains address technical hurdles before transitioning practical It an field; paraphrase Faraday: provide most science. Enjoy fun!