TY - JOUR
T1 - Particle generation of low vapor pressure analytes for an on-demand aerosol standard
AU - Roberts, James G.
AU - Katilie, Christopher J.
AU - Aduba, Donald C.
AU - Giordano, Braden C.
AU - Collins, Greg E.
N1 - Publisher Copyright:
©, This work was authored as part of the Contributor's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.
PY - 2021
Y1 - 2021
N2 - The continual or on-demand delivery of aerosol is important for sensor validation and the development of trace particle detection methodologies. The system presented here operates by introducing aerosolized analytical standard solutions in a heated air flow, generating vapor phase analytes that are subsequently transported and cooled to provide aerosolized particles. The notable design feature was a small concentric air flow device that blends chilled dry air with vapor phase analyte to induce a phase transition without the need for volatile organic solvents. While organic solvents accelerate solvent evaporation, they present potential interferences for downstream sensors. Cyclotrimethylenetrinitramine (RDX) particles were generated and optically counted from the exhaust plume aerosol. The solid RDX material was binned into 1–2.5, 2.5–5, 5–10, and 10+ µm diameter sizes and when the system was actively cooled, the generation of particles exhibited a relative increase of 4.9%, 27.6%, 95.6%, and 78.0% in production, respectively. When observed under a microscope, collected RDX particles ranged from about 1 to 7 µm in diameter. It was determined that the production of solid material was proportional to the temperature and mass loading of the vapor, as dictated by the feed solution concentration; cooler temperatures and higher concentrations led to the increased production of particles ranging from 1 to 10 μm in diameter for the low-vapor pressure analytes studied: RDX (cyclotrimethylenetrinitramine), PETN (pentaerythritol tetranitrate), TNT (2-methyl-1,3,5-trinitrobenzene), and 2,6-DNT (2,6-dinitrotoluene).
AB - The continual or on-demand delivery of aerosol is important for sensor validation and the development of trace particle detection methodologies. The system presented here operates by introducing aerosolized analytical standard solutions in a heated air flow, generating vapor phase analytes that are subsequently transported and cooled to provide aerosolized particles. The notable design feature was a small concentric air flow device that blends chilled dry air with vapor phase analyte to induce a phase transition without the need for volatile organic solvents. While organic solvents accelerate solvent evaporation, they present potential interferences for downstream sensors. Cyclotrimethylenetrinitramine (RDX) particles were generated and optically counted from the exhaust plume aerosol. The solid RDX material was binned into 1–2.5, 2.5–5, 5–10, and 10+ µm diameter sizes and when the system was actively cooled, the generation of particles exhibited a relative increase of 4.9%, 27.6%, 95.6%, and 78.0% in production, respectively. When observed under a microscope, collected RDX particles ranged from about 1 to 7 µm in diameter. It was determined that the production of solid material was proportional to the temperature and mass loading of the vapor, as dictated by the feed solution concentration; cooler temperatures and higher concentrations led to the increased production of particles ranging from 1 to 10 μm in diameter for the low-vapor pressure analytes studied: RDX (cyclotrimethylenetrinitramine), PETN (pentaerythritol tetranitrate), TNT (2-methyl-1,3,5-trinitrobenzene), and 2,6-DNT (2,6-dinitrotoluene).
KW - Mark Swihart
UR - http://www.scopus.com/inward/record.url?scp=85116396329&partnerID=8YFLogxK
U2 - 10.1080/02786826.2021.1977776
DO - 10.1080/02786826.2021.1977776
M3 - Article
AN - SCOPUS:85116396329
SN - 0278-6826
VL - 56
SP - 134
EP - 145
JO - Aerosol Science and Technology
JF - Aerosol Science and Technology
IS - 2
ER -