Size Distribution and Characteristics of Airborne Unrefined Carbon Nanotube Particles

Details

• Personal Author:
  Cohen BS ; Heikkinen MSA ; Xiong JQ
• Description:
  Carbon nanotubes (CNTs) are among the most dynamic and fast-growing nanomaterials due to their novel properties. With a compound annual global production growth rate of well above 60%, the potential of human exposure to this new type material in the workplace as well as in the general environment are rising, and their impacts on human health are of largely concern. A method has been developed in our laboratory for sampling, quantifying and characterizing airborne CNT particles utilizing a 13-stage Electrical Low Pressure Impactor (ELPI) combined with image analysis by Atomic Force Microscopy (AFM). The method is capable of identifying agglomerated nanoparticles in the presence of other airborne particles, and measuring size-resolved number concentrations. The technology has been applied for sampling and characterizing airborne unrefined CNT samples (raw material) of various types including single-walled (SWNT), double-walled (DWNT) and multi-walled (MWNT) nanotubes. The experimental data showed that the particle sizes generated from all types of CNT raw materials were widely distributed across all 13 stages of the ELPI including the filter stage ranging from 7 nm to 10 um in diameter. The particle size distributions varied with the type of CNTs and with the methods by which they were manufactured. AFM results also showed that the CNTs tend to agglomerate rather than exist as single particles, physically. As deposition efficiency and sites of inhaled particles within the respiratory system largely depends on particle size, the deposition pattern of agglomerated nanoparticles should be similar to those larger equivalent sized non-agglomerated particles. Nevertheless, entrained particles depositing on/in the deep lung surfaces of the bronchioles or alveoli will contact pulmonary surfactants in the surface hypophase and the agglomerated CNT are likely to (ultimately) be deagglomerated. Therefore, to investigate human exposure to airborne CNTs, the full size range of inhalable particles must be taken into account. [Description provided by NIOSH]
• Subjects:
  Aerosols Environmental Monitoring Occupational Health Particulate Matter Safety
• Keywords:
  Aerosol Particles Air Sampling Equipment Carbon Nanotubes CNT Exposure Assessment Humans Nanomaterials Nanoparticles Particle Counters Particle Size
• Publisher:
  American Association for Aerosol Research
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Abstract or Summary
• Place as Subject:
  New York ; OSHA Region 2
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• NIOSHTIC Number:
  nn:20058612
• Citation:
  Proceedings of the AAAR 26th Annual Conference, September 24-28, 2007, Reno, Nevada. Mt. Laurel, NJ: American Association for Aerosol Research, 2007 Sep; :12B.2
• CAS Registry Number:
  Carbon nanotubes (CAS RN 308068-56-6)
• Federal Fiscal Year:
  2007
• Performing Organization:
  New York University School of Medicine
• Peer Reviewed:
  False
• Start Date:
  20050801
• Source Full Name:
  Proceedings of the AAAR 26th Annual Conference, September 24-28, 2007, Reno, Nevada
• End Date:
  20090731
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:f7a86020c73217ea6f66724630dee03aecb11ce84f025a787badb14c0af180962fa0e516825748d657a112facf5cbbd9697fdebeb7f6e56d29c1ef56a3884eff
• Download URL:
  https://stacks.cdc.gov/view/cdc/221656/cdc_221656_DS1.pdf
• File Type:
  [PDF - 340.84 KB ]