INCIPIENT SOOT PARTICLES CHARACTERIZATION BY A COMBINATION OF SPECTROSCOPIC TECHNIQUES

In this work, incipient soot particles collected from a laminar premixed flame, have been analyzed, to gain further insights in their chemical composition and on the mechanisms leading to their nucleation. Raman spectroscopy, proton nuclear magnetic resonance (1H-NMR) and electron paramagnetic resonance (EPR) spectroscopy have been used. The combination of these different techniques provides relevant information about the molecular composition of the incipient particles and the relevance of the different types of carbon-bonded hydrogens. Based on the results obtained by EPR spectroscopy, a technique for studying materials with unpaired electrons, a discussion on the role and the possible origin of resonantly stabilized radicals is included.