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Title: Investigation of refractory black carbon-containing particle morphologies using the single-particle soot photometer (SP2)

An important source of uncertainty in radiative forcing by absorbing aerosol particles is the uncertainty in their morphologies (i.e., the location of the absorbing substance on/in the particles). To examine the effects of particle morphology on the response of an individual black carbon-containing particle in a Single-Particle Soot Photometer (SP2), a series of experiments was conducted to investigate black carbon-containing particles of known morphology using Regal black (RB), a proxy for collapsed soot, as the light-absorbing substance. Particles were formed by coagulation of RB with either a solid substance (sodium chloride or ammonium sulfate) or a liquid substance (dioctyl sebacate), and by condensation with dioctyl sebacate, the latter experiment forming particles in a core-shell configuration. Each particle type experienced fragmentation (observed as negative lagtimes), and each yielded similar lagtime responses in some instances, confounding attempts to differentiate particle morphology using current SP2 lagtime analysis. SP2 operating conditions, specifically laser power and sample flow rate, which in turn affect the particle heating and dissipation rates, play an important role in the behavior of particles in the SP2, including probability of fragmentation. This behavior also depended on the morphology of the particles and on the thermo-chemical properties of the non-RB substance. Althoughmore » these influences cannot currently be unambiguously separated, the SP2 analysis may still provide useful information on particle mixing states and black carbon particle sources.« less
Authors:
 [1] ;  [1] ;  [2] ;  [2] ;  [3]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States)
  2. Aerodyne Research, Inc., Billerica, MA (United States); Boston College, Chestnut Hill, MA (United States)
  3. Boston College, Chestnut Hill, MA (United States)
Publication Date:
OSTI Identifier:
1213369
Report Number(s):
BNL--108214-2015-JA
Journal ID: ISSN 0278-6826; R&D Project: 2016-BNL-EE630EECA-Budg; KP1701000
Grant/Contract Number:
SC00112704
Type:
Accepted Manuscript
Journal Name:
Aerosol Science and Technology
Additional Journal Information:
Journal Volume: 49; Journal Issue: 10; Journal ID: ISSN 0278-6826
Publisher:
American Association for Aerosol Research
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES