Carbon | 2019
Relating aerosol mass spectra to composition and nanostructure of soot particles
Abstract
Abstract The composition and carbon nanostructure of soot are important parameters influencing health and climate effects, and the efficacy of soot mitigation technologies. We used laser-vaporization, electron-ionization aerosol mass spectrometry (or SP-AMS) to systematically investigate relationships between aerosol mass spectra, carbon nanostructure (HRTEM), and composition (thermal-optical carbon analysis) for soot with varying physicochemical properties. SP-AMS refractory black carbon concentrations (based on C ≤ 5 + clusters) were correlated to elemental carbon (r\u202f=\u202f0.98, p\u202f C ≥ 6 + , midcarbons and fullerene carbons) fraction was inversely correlated to fringe length (r\u202f=\u202f−0.97, p\u202f=\u202f0.028) and linearly correlated to the fraction of refractory organic carbon that partially pyrolize during heating (r\u202f=\u202f0.89, p\u202f C ≤ 5 + ) indicate mature soot and large carbons indicate refractory organic carbon and amorphous nanostructures related to C5-components. These results have implications for assessments of soot particle mixing state and brown carbon absorption in the atmosphere and enable novel, on-line analysis of engineered carbon nanomaterials and soot characteristics relevant for climate and health.