Formation of hollow and solid carbon spheres in thermally stressed jet fuel in the low temperature autoxidation regime

Abstract

We report the formation of hollow and solid carbon spheres and spherical nanostructures by self-assembly through thermal stressing of jet fuel (Jet A-1) in the autoxidation temperature range. The characterization of Jet A-1 deposits was conducted by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) with energy dispersive x-ray spectroscopy (EDS). Additionally, high resolution mass spectrometry with electro spray ionization source (ESI-MS) have been used to identify large molecular weight compounds in the mass range 350 Da to 1000 Da in the thermally stressed fuel. Fourier transform infrared (FTIR) spectroscopy analysis revealed oxygenated functional groups in the jet fuel treated by flask tests. Compositional analysis of deposit by TEM EDS and scanning transmission electron microscopy (STEM) and a high-angle annular dark field (HAADF) detector identified multiple trace metallic elements such as Cu, Fe, Zn, Sn, Mg, Al and heteroatoms S, N, O. Hollow carbon sphere formation was due to the catalytic activity of trace metals. Spherical particle growth in this method also appeared to follow Ostwald ripening mechanism. Simple flask static tests in the low temperature regime with jet fuel as hydrocarbon source without externally added catalysts thus is a novel method for hollow and solid carbon sphere synthesis and presented in this paper.