Combustion and Flame, Vol.215, 324-332, 2020
Synthesis, characterization and nanoenergetic utilizations of fluorine, oxygen co-functionalized graphene by one-step XeF2 exposure
The energetic performance of aluminum(Al)-based nanothermite composites is hindered by the native alumina shell on the surface of Al nanoparticles. To maximize the energetic release and lower the reaction temperature between Al and metal oxide nanoparticles, a novel fluorine and oxygen co-functionalized graphene (FGO) is reported. The material was synthesized by gas-solid reaction between graphene oxide paper and XeF2 gas. The stability of FGO in atmospheric humidity, heating, and exfoliation by sonication in different solvents were obtained by FTIR and SEM-EDS. The FGO contained both unstable acyl fluoride groups and stable carbon-fluorine covalent/semi-ionic bonds in its structure. The FGO was introduced as a functional additive in an Al/Bi2O3 nanothermite composite, leading to a heat of reaction heat of 1123 J/g, 58% greater than that from loose Al/Bi2O3 powder. The reaction completed before reaching the melting temperature of Al, indicating a novel all-solid-state reaction between Al and Bi2O3. The decreased reaction temperature is attributed to fluorine etching of the native alumina shell surrounding the Al nanoparticle fuel. Keywords: Nanomaterial Graphene Fluorinated graphene Nanothermite fuel. (C) 2020 The Combustion Institute. Published by Elsevier Inc. All rights reserved.