skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Modification of laminar flow ultrafine condensation particle counters for the enhanced detection of 1 nm condensation nuclei

Abstract

This paper describes simple modifications to thermally diffusive laminar flow ultrafine condensation particle counters (UCPCs) that allow detection of {approx}1 nm condensation nuclei with much higher efficiencies than have been previously reported. These nondestructive modifications were applied to a commercial butanol based UCPC (TSI 3025A) and to a diethylene glycol-based UCPC (UMN DEG-UCPC). Size and charge dependent detection efficiencies using the modified UCPCs (BNL 3025A and BNL DEGUCPC) were measured with high resolution mobility classified aerosols composed of NaCl, W, molecular ion standards of tetraalkyl ammonium bromide, and neutralizer-generated ions. With negatively charged NaCl aerosol, the BNL 3025A and BNL DEGUCPC achieved detection efficiencies of 37% (90x increase over TSI 3025A) at 1.68 nm mobility diameter (1.39 nm geometric diameter) and 23% (8x increase over UMN DEG-UCPC) at 1.19 nm mobility diameter (0.89 nm geometric diameter), respectively. Operating conditions for both UCPCs were identified that allowed negatively charged NaCl and W particles, but not negative ions of exactly the same mobility size, to be efficiently detected. This serendipitous material dependence, which is not fundamentally understood, suggests that vapor condensation might sometimes allow for the discrimination between air 'ions' and charged 'particles.' As a detector in a scanning mobility particle spectrometermore » (SMPS), a UCPC with this strong material dependence would allow for more accurate measurements of sub-2 nm aerosol size distributions due to the reduced interference from neutralizer-generated ions and atmospheric ions, and provide increased sensitivity for the determination of nucleation rates and initial particle growth rates.« less

Authors:
; ; ;
Publication Date:
Research Org.:
BROOKHAVEN NATIONAL LABORATORY (BNL)
Sponsoring Org.:
DOE - OFFICE OF SCIENCE
OSTI Identifier:
1033213
Report Number(s):
BNL-95331-2011-JA
Journal ID: ISSN 0278-6826; ASTYDQ; R&D Project: 2012-BNL-EE630EECA-BUDG; KP1701000; TRN: US1200310
DOE Contract Number:  
DE-AC02-98CH10886
Resource Type:
Journal Article
Journal Name:
Aerosol Science and Technology
Additional Journal Information:
Journal Volume: 46; Journal Issue: 3; Journal ID: ISSN 0278-6826
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 74 ATOMIC AND MOLECULAR PHYSICS; AEROSOLS; AIR; ANIONS; BNL; BUTANOLS; CONDENSATION NUCLEI; DETECTION; LAMINAR FLOW; MODIFICATIONS; MOLECULAR IONS; NUCLEATION; RESOLUTION; SENSITIVITY; SPECTROMETERS; VAPOR CONDENSATION

Citation Formats

Kuang, C., Chen, M., McMurry, P. H., and Wang, J. Modification of laminar flow ultrafine condensation particle counters for the enhanced detection of 1 nm condensation nuclei. United States: N. p., 2011. Web.
Kuang, C., Chen, M., McMurry, P. H., & Wang, J. Modification of laminar flow ultrafine condensation particle counters for the enhanced detection of 1 nm condensation nuclei. United States.
Kuang, C., Chen, M., McMurry, P. H., and Wang, J. Sat . "Modification of laminar flow ultrafine condensation particle counters for the enhanced detection of 1 nm condensation nuclei". United States.
@article{osti_1033213,
title = {Modification of laminar flow ultrafine condensation particle counters for the enhanced detection of 1 nm condensation nuclei},
author = {Kuang, C. and Chen, M. and McMurry, P. H. and Wang, J.},
abstractNote = {This paper describes simple modifications to thermally diffusive laminar flow ultrafine condensation particle counters (UCPCs) that allow detection of {approx}1 nm condensation nuclei with much higher efficiencies than have been previously reported. These nondestructive modifications were applied to a commercial butanol based UCPC (TSI 3025A) and to a diethylene glycol-based UCPC (UMN DEG-UCPC). Size and charge dependent detection efficiencies using the modified UCPCs (BNL 3025A and BNL DEGUCPC) were measured with high resolution mobility classified aerosols composed of NaCl, W, molecular ion standards of tetraalkyl ammonium bromide, and neutralizer-generated ions. With negatively charged NaCl aerosol, the BNL 3025A and BNL DEGUCPC achieved detection efficiencies of 37% (90x increase over TSI 3025A) at 1.68 nm mobility diameter (1.39 nm geometric diameter) and 23% (8x increase over UMN DEG-UCPC) at 1.19 nm mobility diameter (0.89 nm geometric diameter), respectively. Operating conditions for both UCPCs were identified that allowed negatively charged NaCl and W particles, but not negative ions of exactly the same mobility size, to be efficiently detected. This serendipitous material dependence, which is not fundamentally understood, suggests that vapor condensation might sometimes allow for the discrimination between air 'ions' and charged 'particles.' As a detector in a scanning mobility particle spectrometer (SMPS), a UCPC with this strong material dependence would allow for more accurate measurements of sub-2 nm aerosol size distributions due to the reduced interference from neutralizer-generated ions and atmospheric ions, and provide increased sensitivity for the determination of nucleation rates and initial particle growth rates.},
doi = {},
journal = {Aerosol Science and Technology},
issn = {0278-6826},
number = 3,
volume = 46,
place = {United States},
year = {2011},
month = {10}
}