Perfluoroalkyl-Functionalized Graphene Oxide as a Multifunctional Additive for Promoting the Energetic Performance of Aluminum

Abstract

Aluminum (Al) is a widely used metal fuel for energetic applications ranging from space propulsion and exploration, and materials processing, to power generation for nano- and microdevices due to its high energy density and earth abundance. Recently, the ignition and combustion performance of Al particles were found to be improved by graphene-based additives, such as graphene oxide (GO) and graphene fluoride (GF), as their reactions provide heat to accelerate Al oxidation, gas to reduce particle agglomeration, and fluorine-containing species to remove Al2O3. However, GF is not only expensive but also hydrophobic with poor mixing compatibility with Al particles. Herein, we report a multifunctional graphene-based additive for Al combustion, i.e., perfluoroalkyl-functionalized graphene oxide (CFGO), which integrates the benefits of GO and GF in one material. We compared the effects of CFGO to GO and GF on the ignition and combustion properties of nAl particles using thermogravimetric analysis, differential scanning calorimetry, temperature-jump ignition), Xe flash ignition, and constant-volume combustion test. These experiments confirm that CFGO generates fluorine-containing species, heat, and gases, which collectively lower the ignition threshold, augment the energy release rate, and reduce the combustion product agglomeration of nanosized Al particles, outperforming both GO and GF as additives. This work shows the great potential of using multifunctionalized graphene as an integrated additive for enhancing the ignition and combustion of metals.

Preparation and Properties of Pyrotechnic Binder Encapsulated α‐AlH3 Composites by Solvent/Anti‐solvent Method

“…In the spectra of the Viton‐coated α‐AlH 3 composite, its Al2p corresponded to two peaks at 73.5 eV and 76.7 eV, which was ascribed to Al−O/Al=O and Al−F. While for F1s two peaks at 689.2 eV and 691.8 eV were ascribed to Al−F and C−F, indicating the interaction between α‐AlH 3 and viton [37] . Besides, for C1s extra peaks ascribed to C−F in viton structural unit showed up except for the C−C (284.6 eV), further proving that viton has been successfully encapsulated on the α‐AlH 3 .…”

Effect of Fluoroalcohol Chain Extension Modified HTPB Binder on the Combustion Performance of Aluminized Propellants

“…While the Al particles tend to aggregate and form larger aggregates, they maintain an irregular structure composed of both solid and liquid phases rather than fully liquefying. As these aggregates continue to melt, the skeletal structure of the Al clusters gradually collapses, transforming into more regular spherical Al droplets [30,31]. Such scattered agglomerates can be clearly seen in the yellow circles in Figure 7a.…”

Exfoliated Magnesium Diboride (MgB2) Nanosheets as Solid Fuels

“…Both the MgB 2 nanosheets and B/Mg nanoparticle mixtures were ignited at 2.1 J/cm 2 to remove the ignition energy impact. Figure a,b shows the snapshots of temperature profiles of the MgB 2 nanosheets and B/Mg nanoparticle mixture in the ambient environment using a high-speed IR camera at 1000 fps. , The temperature window of our IR camera measurement is 616–1400 °C. Only part of the burning temperature of the B/Mg nanoparticles mixture can be recorded, implying that most of the burning temperatures of the mixture particles are below 616 °C.…”