Slip Correction Measurements of Certified PSL Nanoparticles Using a Nanometer Differential Mobillity Analyzer (Nano-DMA) for Knudsen Number From 0.5 to 83

Published

March 1, 2005

Author(s)

Jae H. Kim, George W. Mulholland, S R. Kukuck, D Y. Pui

Abstract

The slip correction factor has been investigated at reduced pressures and high Knudsen number using polystyrene latex (PSL) particles. Nano-differential mobility analyzers (NDMA) were used in determining the slip correction factor by measuring the electrical mobility of 100.7 nm, 269 nm, and 19.90 nm particles as a function of pressure. The aerosol was generated via electrospray to avoid multiplets for the 19.90 nm particles and to reduce the contaminant residue on the particle surface. System pressure was varied down to 8.27 kPa, enabling slip correction measurements for Knudsen numbers as large as 83. A condensation particle counter was modified for low pressure application. The slip correction factor obtained for the three particle sizes is fitted well by the equation: C = 1 + Kn ( a + B exp(-y/Kn)), with a = 1.165, B= 0.483, and y = 0.997. The first quantitative uncertainty analysis for slip correction measurements was carried out. The expanded relative uncertainty (95% confidence interval) in measuring slip correction factor was about 2% for the 100.7 nm SRM particles, about 3 % for the 19.90 nm PSL particles, and about 2.5% for the 269 nm SRM particles. The major sources of uncertainty are the diameter of particles, the geometric constant associated with NDMA, and the voltage.

Citation

Journal of Research (NIST JRES) -

Volume

110 No. 1

NIST Pub Series

Journal of Research (NIST JRES)

Pub Type

NIST Pubs

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Keywords

electrospray, Knudsen number, NMDA, polystyrene latex particles, slip correction factor

Citation

Kim, J. , Mulholland, G. , Kukuck, S. and Pui, D. (2005), Slip Correction Measurements of Certified PSL Nanoparticles Using a Nanometer Differential Mobillity Analyzer (Nano-DMA) for Knudsen Number From 0.5 to 83, Journal of Research (NIST JRES), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=861332 (Accessed April 25, 2024)