Photo-thermal desorption of toluene from single walled carbon nanotube adsorbent pads in air samplers

Details

• Personal Author:
  Floyd E ; Lungu CT ; Oh, Je M.
• Description:
  Activated Carbon (AC) is widely used to collect volatile organic compounds (VOCs) in air samplers. Laboratory analysis is performed by chemical or thermal desorption. Both these methods present limitations with respect to either sensitivity (chemical) or cost (thermal) and are time consuming. A technique that achieves partial desorption and improves sensitivity over chemical desorption would be desirable. Single Walled Carbon Nanotubes (SWNT) have similar VOC adsorption properties as AC. Camera flash has been used to ignite SWNT; therefore, light flash could be used for desorption. We prepared SWNT adsorbent pads, loaded them with toluene vapors and used light flash to achieve partial desorption. Methods: Light flash of different energies is applied to AC and SWNT samples. Samples were loaded with toluene and flashed once per minute. Light is absorbed and converted into heat causing desorption. A photo ionization detector was used to quantify desorbed toluene mass. Results: SWNT-felt desorption was nearly constant across successive flashes whereas SWNT-powder and AC-powder exhibit exponential decrease after first flash. At 435µg toluene and 4.7J flash, first flash and 10-flash desorption was: SWNT-felt 0.86%, 7.71%, SWNT-powder 0.57% and 2.92%, AC-powder 0.34% and 1.37% respectively. Conclusions: Single flash desorption can deliver more sample to an analytical instrument than chemical extraction. SWTN-felt desorption is additive whereas SWNT-powder and AC are exponentially decreasing. [Description provided by NIOSH]
• Subjects:
  Acetone Laboratories Manufacturing And Industrial Facilities Methanol Occupational Health Radiation Safety Solvents Surface-Active Agents Temperature Toluene

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• Keywords:
  Adsorbents Analytical-instruments Analytical-processes Chemical Cleaning Filter Membranes Irradiation Laboratory Techniques Materials-testing Measurement-equipment Nanotechnology Organic-chemicals Organic-compounds Performance-capability Photometry Porous-materials Porous Materials Samlpers Sampling-equipment Sampling Methods Single-walled Carbon Nanotubes Sodium Compounds Sulfates Surface Properties Surfactants SWCNT Temperature Control Thermal-effects Volatiles

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• Publisher:
  International Conferences on Modern Materials and Technologies
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Abstract or Summary
• Place as Subject:
  Alabama ; Oklahoma ; OSHA Region 4 ; OSHA Region 6
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• NIOSHTIC Number:
  nn:20047836
• Citation:
  CIMTEC 2014: 6th Forum on New Materials, June 15- 19, 2014, Montecatini Terme, Pistoia, Italy. Faenza, Italy: CIMTEC 2014, 2014 Jun; :FK-4:L21
• CAS Registry Number:
  Acetone (CAS RN 67-64-1) ; Carbon nanotubes (CAS RN 308068-56-6) ; Methanol (CAS RN 67-56-1) ; Sodium cholate (CAS RN 361-09-1) ; Sodium dodecyl sulfate (CAS RN 151-21-3) ; Toluene (CAS RN 108-88-3)
• Federal Fiscal Year:
  2014
• Performing Organization:
  University of Alabama at Birmingham
• Peer Reviewed:
  False
• Start Date:
  20130901
• Source Full Name:
  CIMTEC 2014: 6th Forum on New Materials, June 15- 19, 2014, Montecatini Terme, Italy
• End Date:
  20150831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:2307d98033641e00af320e1fa6825fbcc5646ec41d2042e4c4b9020474f824b1c0f42c5bcc25c494f3c955d35f29c9913eeb6a14087d38474599affaebab907e
• Download URL:
  https://stacks.cdc.gov/view/cdc/202803/cdc_202803_DS1.pdf
• File Type:
  [PDF - 45.71 KB ]