Radial Differential Mobility Analyzer for One Nanometer Particle Classification

We present details on the design, construction, and calibration of a radial differential mobility analyzer suitable for sizing aerosol nanoparticles with mobility diameters as small as one nanometer. Design improvements targeted decreasing the residence time with a concomitant reduction in particle agglomeration and diffusional losses to walls. Calibration was performed using aerosolized monodisperse molecular ions. Instrument resolution was found to increase with applied voltage as V 1/2 , indicating that diffusion is broadening the transfer function and reaching a value of ∼7 for the largest molecular ion measured (mobility diameter of 1.47 nm). The mobilities of three molecular ions in the tetra-alkyl ammonium halide homologous series are also reported.

[1]  J. Mora Diffusion broadening in converging differential mobility analyzers , 2002 .

[2]  Richard C. Flagan,et al.  History of Electrical Aerosol Measurements , 1998 .

[3]  Hannes Tammet,et al.  Size and mobility of nanometer particles, clusters and ions , 1995 .

[4]  T. A. Taton,et al.  Thermal transport in au-core polymer-shell nanoparticles. , 2005, Nano letters.

[5]  P. Martínez-Lozano,et al.  Resolution improvements of a nano-DMA operating transonically , 2006 .

[6]  Heinz Fissan,et al.  Design and evaluation of a nanometer aerosol differential mobility analyzer (Nano-DMA) , 1998 .

[7]  Alla Zelenyuk,et al.  From Agglomerates of Spheres to Irregularly Shaped Particles: Determination of Dynamic Shape Factors from Measurements of Mobility and Vacuum Aerodynamic Diameters , 2006 .

[8]  S. Rosser,et al.  Vienna-Type DMA of High Resolution and High Flow Rate , 2005 .

[9]  H. Fissan,et al.  Analytical and empirical transfer functions of a simplified spectromètre de mobilité electrique circulaire (SMEC) for nano particles , 1998 .

[10]  R. Flagan On Differential Mobility Analyzer Resolution , 1999 .

[11]  Kikuo Okuyama,et al.  Effect of brownian diffusion on electrical classification of ultrafine aerosol particles in differential mobility analyzer , 1986 .

[12]  K. T. Whitby,et al.  Aerosol classification by electric mobility: apparatus, theory, and applications , 1975 .

[13]  J. Rosell-Llompart,et al.  Sizing nanoparticles and ions with a short differential mobility analyzer , 1996 .

[14]  J. Mora,et al.  Molecular monodisperse mobility and mass standards from electrosprays of tetra-alkyl ammonium halides , 2005 .

[15]  R. M. Sankaran,et al.  Synthesis of blue luminescent si nanoparticles using atmospheric-pressure microdischarges. , 2005, Nano letters.

[16]  Peter H. McMurry,et al.  A review of atmospheric aerosol measurements , 2000 .

[17]  J. F. D. L. Mora,et al.  High resolution size analysis of nanoparticles and ions , 1998 .