Generation and characterization of aerosols released from sanding composite nanomaterials containing carbon nanotubes

Details

• Personal Author:
  Afshari A ; Bunker K ; Casuccio G ; Cena L ; Dahm, Matthew M. ; Erdely A ; Farcas D ; Kang J ; Lersch T
• Description:
  An adaptable system was developed to generate and characterize particles released from composite materials containing carbon nanotubes (CNTs). The system was tested with a belt sander by sanding 1) glass fiber/epoxy resin, 2) acrylonitrile butadiene styrene (ABS), and 3) ABS with carbon black. Each material was tested with fine and coarse sandpaper in its neat form and with CNT additives. Total number concentrations, respirable mass concentrations, and particle number/ mass distributions of the released particles were measured with a combination of direct-read instruments. Airborne particle samples for electron microscopy analysis were collected on polycarbonate filters, and onto a transmission electron microscopy grid supported carbon film using a thermophoretic sampler. Using automated microscopy analysis and a newly developed method, over 200 particles from each filter sample were analyzed for chemical composition, size, and the presence of CNT protrusions. Direct-read instruments revealed that the highest number and mass concentrations were generated with Material 1 (6 × 104 particles/cm3 and 0.5 mg/m3 with coarse sandpaper) and that the addition of CNTs decreased number concentrations (4.5 × 104 particles/cm3 with coarse sandpaper). Respirable concentrations of the materials containing CNTs were higher than the respective base materials without additives with the exception of Material 1 with coarse sandpaper. Microscopy analysis results indicated that particles were primarily micrometer-sized and some particles had protruding features. From the chemical analysis, the percentages of particles generated during sanding that were attributable to the deterioration of sandpaper were 59-83% for Material 1 and 6-27% for Materials 2 and 3. The highest number of protrusions were found in Material 3 with CNT additive and fine sandpaper (3.71 average protrusions per particle) while the lowest number or protrusions were found in Material 2 with short CNTs and fine sandpaper (0.66 average protrusions per particle). No free-standing CNTs were observed in the samples. The combination of direct-read instruments and automated electron microscopy provides greater insights in particle chemistry, size measurements and CNT associations. [Description provided by NIOSH]
• Subjects:
  Aerosols Occupational Health Safety
• Keywords:
  Author Keywords: Composite Materials Carbon Nanotubes CNT Computer Controlled Scanning Electron Microscopy Nanoparticles Release Scanning Electron Microscopy
• ISSN:
  2452-0748
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  Ohio ; OSHA Region 3 ; OSHA Region 5 ; Pennsylvania ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division ; DSHEFS - Division of Surveillance, Hazard Evaluations, and Field Studies
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  41-50
• Volume:
  5
• NIOSHTIC Number:
  nn:20049117
• Citation:
  NanoImpact 2017 Jan; 5:41-50
• Email:
  LCena@wcupa.edu
• Federal Fiscal Year:
  2017
• NORA Priority Area:
  Manufacturing
• Peer Reviewed:
  True
• Source Full Name:
  NanoImpact
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:3b2c60b0306ba7ddb181de2a04a914a942cebeecac378ed66ff872b875a159b1daec1ca5810cffa71435080fb129285a4486bbcad1e233fe3610005aa148e352
• Download URL:
  https://stacks.cdc.gov/view/cdc/203685/cdc_203685_DS1.pdf
• File Type:
  [PDF - 1.07 MB ]