Implications of Thermal Annealing on the Benzene Vapor Sensing Behavior of PEVA-Graphene Nanocomposite Threads

Details

• Personal Author:
  Anderson R ; Cemalovic S ; Fruhberger B ; Hobson ST ; Patel SV ; Tolley, William K.
• Description:
  The effect of thermal treatments, on the benzene vapor sensitivity of polyethylene (co-)vinylacetate (PEVA)/graphene nanocomposite threads, used as chemiresistive sensors, was investigated using DC resistance measurements, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). These flexible threads are being developed as low-cost, easy-to-measure chemical sensors that can be incorporated into smart clothing or disposable sensing patches. Chemiresistive threads were solution-cast or extruded from PEVA and <10% graphene nanoplatelets (by mass) in toluene. Threads were annealed at various temperatures and showed up to 2 orders of magnitude decrease in resistance with successive anneals. Threads heated to >/= 80 degrees C showed improved limits of detection, resulting from improved signal-noise, when exposed to benzene vapor in dry air. In addition, annealing increased the speed of response and recovery upon exposure to and removal of benzene vapor. DSC results showed that the presence of graphene raises the freezing point, and may allow greater crystallinity, in the nanocomposite after annealing. SEM images confirm increased surface roughness/area, which may account for the increase response speed after annealing. Benzene vapor detection at 5 ppm is demonstrated with limits of detection estimated to be as low as 1.5 ppm, reflecting an order of magnitude improvement over unannealed threads. [Description provided by NIOSH]
• Subjects:
  Benzene Occupational Health Safety Solvents Toluene
• Keywords:
  Author Keywords: PEVA Benzene Vapor Sensor Chemicals Chemical Sensor Chemiresistor Electron Microscopy Exposure Monitor Graphene Nanocomposites Nanoplatelets Polymer Nanocomposite Sensors Toluenes Vapors Wearable Sensors

  More +
• ISSN:
  2379-3694
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  California ; OSHA Region 9
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  3
• Issue:
  3
• NIOSHTIC Number:
  nn:20051094
• Citation:
  ACS Sens 2018 Mar; 3(3):640-647
• Contact Point Address:
  Sanjay V. Patel, Seacoast Science, Inc., 2151 Las Palmas Drive, Suite C, Carlsbad, California 92011, United States
• Email:
  sanjay@seacoastscience.com
• CAS Registry Number:
  Benzene (CAS RN 71-43-2) ; Graphene (CAS RN 1034343-98-0) ; Toluene (CAS RN 108-88-3)
• Federal Fiscal Year:
  2018
• Performing Organization:
  Seacoast Science, Inc., Carlsbad, California
• Peer Reviewed:
  True
• Start Date:
  20160901
• Source Full Name:
  ACS Sensors
• End Date:
  20170228
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:5ae71cf3f67cc9463260cedefeb86965169eae874744c4ab3519d134d6db2e4f92629ad06defde927a3dbe1bd66af235872f4f45fbfd26b73db659109cfa20e0
• Download URL:
  https://stacks.cdc.gov/view/cdc/211220/cdc_211220_DS1.pdf
• File Type:
  [PDF - 957.81 KB ]