The structural analysis of condensed phases, including condensed species and soot, has been carried out by using FT-IR and UV-Visible spectroscopy sensitive to the hydrogen bonding and carbon network, respectively.
The very low hydrogenated character, as evaluated by FT-IR and elemental analysis, and the high aromatic/graphitic nature of the benzene soot, as shown by a detailed examination of UV-Visible spectral parameters, confirmed the effect of benzene fuel on the internal structure of soot particles already in the early stages of particle inception.