Aromatic excimers: evidence for polynuclear aromatic hydrocarbon condensation in flames

Miller, J. Houston

doi:10.1016/j.proci.2004.08.192

Cited by 62 publications

(23 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[26b] Several recent studies have placed the limit for the physical agglomeration of PAH at sizes even larger (> 700 Da) than observed here. [34] This has led to suggestions that more complex chemistry may play a role in in PP formation including aromatic excimer formation [35] (perhaps with aliphatic linkages [36] ) through radical [37] (or diradicals [38] ), or "rim-bonding". [39] The data presented here, as well as in contemporary studies showing evidence for PAH clustering, [40] provides proof that species of sufficient size are present and that their size is consistent with the conjugation length inferred by both Raman scattering and optical band gap measurements observed in the same burner/flame system.…”

Section: Resultsmentioning

confidence: 99%

The Molecular Composition of Soot

et al. 2020

Self Cite

View full text Add to dashboard Cite

Soot (sometimes referred to as black carbon) is produced when hydrocarbon fuels are burned. Our hypothesis is that polynuclear aromatic hydrocarbon (PAH) molecules are the dominant component of soot, with individual PAH molecules forming ordered stacks that agglomerate into primary particles (PP). Here we show that the PAH composition of soot can be exactly determined and spatially resolved by low‐fluence laser desorption ionization, coupled with high‐resolution mass spectrometry imaging. This analysis revealed that PAHs of 239–838 Da, containing few oxygenated species, comprise the soot observed in an ethylene diffusion flame. As informed by chemical graph theory (CGT), the vast majority of species observed in the sampled particulate matter may be described as benzenoids, consisting of only fused 6‐membered rings. Within that limit, there is clear evidence for the presence of radical PAH in the particulate samples. Further, for benzenoid structures the observed empirical formulae limit the observed isomers to those which are nearly circular with high aromatic conjugation lengths for a given aromatic ring count. These results stand in contrast to recent reports that suggest higher aliphatic composition of primary particles.

show abstract

Section: Resultsmentioning

confidence: 99%

The Molecular Composition of Soot

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…In this paper, we demonstrate that this hypothesis is also very unlikely. Finally, a few papers in the literature exist supporting the idea that these signals could be issued from the fluorescence of dimers of PAHs 31,32 nm excitation wavelengths. After the laser output, the laser beam was slightly focused at the center of the diffusion methane/air flame using a spherical UV lens (f=1000 mm).…”

Section: Introductionmentioning

confidence: 93%

Dimers of polycyclic aromatic hydrocarbons: the missing pieces in the soot formation process

Mercier

Carrivain

Irimiea

et al. 2019

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…These young particles are thought to be formed from fast coalescence of precursor particles acting as a nuclei for the condensation of gas phase species [10,15,16,17]. The nuclei (1-3 nm) are thought to be formed by the collision of polycyclic aromatic hydrocarbon (PAH) molecules [16,18] and clusters of them [15,19,20], as revealed by HRTEM images of soot particles [21,17].…”

Section: Introductionmentioning

confidence: 99%