Detection of sub-5nm naturally charged carbonaceous materials from a sooting laminar premixed flame by a water condensation Particle Counter (WCPC) enhanced by a Di-Ethylene Glycol (DEG) saturator inlet

Abstract

Combustion is one of the major contributors to air pollution and Condensation Particle Counters (CPCs) provide effective monitoring of atmospheric aerosols since they can detect both charged and neutral materials in low number concentrations. The detection efficiency of any CPC for materials smaller than 5 nm requires ad-hoc calibrations because it is affected by the analyte’s size, shape, charge state, composition, and wettability by the condensing fluid. This study characterizes a Water-based CPC (WCPC) prototype for the detection of the naturally charged carbonaceous products of an incipiently sooting laminar premixed flame. The WCPC can activate condensation growth and (50% efficient) detection of hydrophobic flame-formed carbonaceous materials naturally charged in positive and negative polarities with mobility diameters as small as 4.3 nm and 4.8 nm, respectively. The addition of a simple Di-Ethylene Glycol (DEG) saturator inlet enhances the 50% detection cutoff to mobility diameters as small as 1.8 nm or 1.6 nm for materials charged in positive or negative polarity, respectively. The coupling of the DEG saturator inlet to the WCPC creates a new DEG-WCPC instrument able to detect efficiently both hydrophobic and hydrophilic sub-5nm aerosols with a marginal increase in manufacturing cost (<10%), dimensions, and weight (<0.25 kg).

Copyright © 2023 American Association for Aerosol Research

Graphical Abstract

EDITOR:

• Jingkun Jiang

Acknowledgments

This work acknowledges Chongai Kuang for the concept and initial development efforts of the DEG inlet, as part of the project PASCCALS (Process-level AdvancementS of Climate through Cloud and Aerosol Lifecycle Studies), funded by the Office of Biological and Environmental Research in the Department of Energy, Office of Science, and through the United States Department of Energy contract no. DE-SC0012704 to Brookhaven National Laboratory.

Disclaimer

Gregory S. Lewis and Arantza Eiguren-Fernandez declare to be shareholders of Aerosol Dynamics Inc. which designed, manufactured, and owns the tested ADI-2021-1 WCPC prototype.

Additional information

Funding

Financial support for this work is being provided by the USA National Science Foundation (Grant#CBET- 2013382, Prof. Harsha K. Chelliah serving as Program Manager).