Enhancing the Combustion Performance of Metastable Al@AP/PVDF Nanocomposites by Doping with Graphene Oxide

A new group of energetic metastable intermixed composites (MICs) was designed and fabricated by means of the spray granulation technique. These MICs are composed of aluminum (Al) as the fuel, ammonium perchlorate (AP) and polyvinylidene fluoride (PVDF) as the co-oxidizer. The AP/PVDF ratio was optimized by taking the maximum energy release as the criteria. A minor content of graphene oxide (GO) was also doped in the MICs to act as both lubricant and catalyst. It was shown that Al@AP/PVDF with 0.2% GO has the greatest density (2.57 g·cm⁻³) and highest heat of reaction (5999.5 J·g⁻¹). These values are much higher than those of Al@AP/PVDF (2.00 g·cm⁻³ and 5569.8 J·g⁻¹). The inclusion of GO increases the solid-state reaction rate of Al@AP/PVDF and improves the thermal stability. The flame propagation rate was increased up to 4.76 m·s⁻¹ by doping with 0.2% GO, and was about 10.7% higher than that of Al@AP/PVDF. Al@AP/PVDF-GO has a better interfacial contact and particle distribution, which results in an improved heat-transfer rate, freedom from the agglomeration of nano-Al particles, and an improved combustion reaction rate. This work demonstrates a new strategy to improve the energy release rate and combustion efficiency of Al-based MICs.