Slip Correction Measurements of Certified PSL Nanoparticles Using a Nanometer Differential Mobility Analyzer (Nano-DMA) for Knudsen Number From 0.5 to 83.
Slip Correction Measurements of Certified PSL Nanoparticles Using a Nanometer Differential Mobility Analyzer (Nano-DMA) for Knudsen Number From 0.5 to 83.
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DOI：
10.6028/jres.110.005
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发表时间：
2005-01
影响因子：
1.5
通讯作者：
Pui DY
中科院分区：
文献类型：
--
作者：
Kim JH;Mulholland GW;Kukuck SR;Pui DY
在减压和高努森数下，用聚苯乙烯胶乳（PSL）颗粒研究了滑移修正因子。纳米微分迁移率分析仪（NDMA）用于通过测量作为压力的函数的100.7 nm、269 nm和19.90 nm颗粒的电迁移率来确定滑移校正因子。通过电喷雾产生气溶胶，以避免19.90 nm颗粒的多重峰，并减少颗粒表面上的污染物残留。系统压力变化到8.27千帕，使滑移校正测量努森数大至83。对冷凝式粒子计数器进行了改进，使之适用于低压环境.三种粒径的滑移修正系数可以很好地用以下公式拟合：C = 1 + Kn（α + β exp（−γ/Kn）），其中α = 1.165，β = 0.483，γ = 0.997。进行了滑移修正测量的第一次定量不确定度分析。测量滑移校正因子的扩展相对不确定度（95%置信区间）对于100.7 nm SRM颗粒约为2%，对于19.90 nm PSL颗粒约为3%，对于269 nm SRM颗粒约为2.5%。不确定性的主要来源是颗粒的直径、与NDMA相关的几何常数和电压。
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 (α + β exp(−γ/Kn)), with α = 1.165, β = 0.483, and γ = 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.