Relation Between Electrical Mobility, Mass, and Size for Nanodrops 1–6.5 nm in Diameter in Air

Details

• Personal Author:
  de la Mora JF ; Ku BK
• Description:
  A large number of data on mobility and mass have been newly obtained or reanalyzed for clusters of a diversity of materials, with the aim of determining the relation between electrical mobility (Z) and mass diameter dm = (6m/pi p)1/3 (m is the particle mass and p the bulk density of the material forming the cluster) for nanoparticles with dm ranging from 1 nm to 6.5 nm. The clusters were generated by electrospraying solutions of ionic liquids, tetra-alkyl ammonium salts, cyclodextrin, bradykinin, etc., in acetonitrile, ethanol, water, or formamide. Their electrical mobilities Z in air were measured directly by a differential mobility analyzer (DMA) of high resolution. Their masses m were determined either directly via mass spectrometry, or assigned indirectly by first distinguishing singly (z = 1) and doubly (z = 2) charged clusters, and then identifying monomers, dimers, . . . n-mers, etc., from their ordering in the mobility spectrum. Provided that dm > 1.3 nm, data of the form dm vs. [z(1+mg/m)1/2/Z)]1/2 fall in a single curve for nanodrops of ionic liquids (ILs) for which p is known (mg is the mass of the molecules of suspending gas). Using an effective particle diameter dp = dm+ dg and a gas molecule diameter dg = 0.300 nm, this curve is also in excellent agreement with the Stokes-Millikan law for spheres. Particles of solid materials fit similarly well the same Stokes-Millikan law when their (unknown) bulk density is assigned appropriately. [Description provided by NIOSH]
• Subjects:
  Aerosols Occupational Health Particulate Matter Safety
• Keywords:
  Aerosol-particles Electrochemical-analysis Electrochemistry Electromagnetic-absorption Mathematical-models Models Nanotechnology Particle-aerodynamics Particle-counters Particulate-sampling-methods Particulates

  More +
• ISSN:
  0278-6826
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  Ohio ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DART - Division of Applied Research and Technology
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  241-249
• Volume:
  43
• Issue:
  3
• NIOSHTIC Number:
  nn:20034937
• Citation:
  Aerosol Sci Technol 2009 Mar; 43(3):241-249
• CAS Registry Number:
  Acetonitrile (CAS RN 75-05-8) ; Formaldehyde (CAS RN 50-00-0)
• Federal Fiscal Year:
  2009
• NORA Priority Area:
  Manufacturing
• Peer Reviewed:
  True
• Source Full Name:
  Aerosol Science and Technology
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:a1b7466ec79e619d79904951dbb1ab7de4ef36a7344d06f451f9002a3e9d67449c962e0a36c0487741363b3b3e391e3801eee54b0fbc638d7d15191a2e77aeda
• Download URL:
  https://stacks.cdc.gov/view/cdc/186952/cdc_186952_DS1.pdf
• File Type:
  [PDF - 353.80 KB ]