Role of graphene as an additional fuel in Al/Fe2O3 nanothermite

Abstract

Interfacial contacts and mass transport between metal oxide and fuel in nanothermites play an important role in the thermal properties of these materials. An investigation of the influence of multi-layered graphene (MLG) as an additional fuel in exothermic reaction of Al/Fe2O3 nanothermite in powder form as well as in compact form was studied in this paper. Al/MLG/Fe2O3 nanothermite powder was synthesized by physical mixing and ultrasonication method. This nanocomposite powder was further compacted in uniaxial molding press, and examine the role of interfacial interaction in thermite reaction. X-ray diffraction (XRD) technique was used to confirm different phases present in the samples. Field emission electron microscopy (FESEM) and energy dispersive spectroscopy (EDS) showed that Al/MLG/Fe2O3 were homogenously mixed and composed of Al, Fe2O3 and MLG. Moreover, the stability of graphene structure was examined by the RAMAN spectroscopy. The energy released by samples was investigated by Differential scanning calorimetry (DSC). The TGA/DSC results indicated that the exothermic behaviour of thermite reaction was affected by the interfacial contacts and diffusion length between the constituent particles. As a result the calculated values for the energy release of Al/Fe2O3 (pure sample), Al/MLG/Fe2O3 (with an additional fuel) and Al/MLG/Fe2O3 (compact powder) nanothermites are-215 J/g, -674 J/g and -1070 J/g respectively.