Molecular structures in flames: A comparison between SNapS2 and recent AFM results

Models capturing the growth of polycyclic aromatic compounds (PACs) and nanoparticles in combustion have always faced a large degree uncertainty due to paucity detailed direct experimental validation. In particular, data on molecular structures, chemical composition, size, cross-linking, aliphatic chains is still very limited. past few years, we developed an atomistic code, SNapS2, that models formation PACs conditions, providing information structural evolution these compounds. this paper, present analysis formed premixed ethylene-air flame was previously characterized experimentally by AFM (Commodo et al. 2019). The comparison based structures extends other properties PACs. results demonstrate SNapS2 able capture vast array terms variety functional groups. simulations, confirmed extent data, show presence different types oxygenated (e.g., phenol, ketone) cyclic (acenaphthylene-type, acenaphthene-type, fluorene-type five-membered rings) Moreover, were not observed simulations (indane-type rings or six-membered containing oxygen) are missing lack pathways, highlighting fact important kinetic mechanisms literature. Finally, preponderant number high mass curved, which may impact their aggregation sampling. Overall, while some discrepancies remain inherent limitation model techniques, work demonstrates unique capabilities code provide insights pathways