title: Measurements of nanoparticles of organic carbon and soot in flames and vehicle exhausts.
abstract: We measured the size distribution and UV extinction spectra of carbonaceous nanoparticles present in the size range of 1-100 nm in the exhausts of 2004 model gasoline and diesel powered vehicles and compared the results with those obtained in premixed flames. In addition to soot particles, nanoparticles of organic carbon (NOC) were measured in the emissions of these test vehicles in significant number and mass concentrations. The number and mass concentration of NOC was higher than soot in gasoline vehicle emissions. In diesel emissions, NOC had a higher number concentration than soot in terms of number concentration, but in terms of mass concentration, soot was higher than NOC. The size (1-3 nm) and extinction spectra in the UV-visible (strong in the UV and transparent in the visible) of macromolecules/nanoparticles collected in water samples from the vehicles are similar to those measured in laboratory hydrocarbon-air flames, suggesting that these nanoparticles are formed in hydrocarbon combustion reactions. We advance the hypothesis that NOC in vehicle emissions are produced by high-temperature combustion processes and not by low-temperature condensation processes.
authors.affiliation: Dipartimento di Ingegneria Chimica, Università "Federico II" di Napoli, P. Tecchio 80, 80125 Naples, Italy. lasgro@yahoo.com
authors.forename: Lee A
authors.initials: LA
authors.lastname: Sgro
authors.forename: Antonio
authors.initials: A
authors.lastname: Borghese
authors.forename: Luciano
authors.initials: L
authors.lastname: Speranza
authors.forename: Alberto C
authors.initials: AC
authors.lastname: Barone
authors.forename: Patrizia
authors.initials: P
authors.lastname: Minutolo
authors.forename: Annalisa
authors.initials: A
authors.lastname: Bruno
authors.forename: Andrea
authors.initials: A
authors.lastname: D'Anna
authors.forename: Antonio
authors.initials: A
authors.lastname: D'Alessio
mesh_terms: D002244:Carbon / Q000737:chemistry*; D005390:Fires; D005742:Gasoline; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D053260:Soot / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D001335:Vehicle Emissions; D014867:Water
chemical_list: D005742:Gasoline; D053260:Soot; D001335:Vehicle Emissions; D014867:Water; D002244:Carbon