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

Details

• Alternative Title:
  ACS Sens
• Personal Author:
  Patel, Sanjay V. ; Cemalovic, Sabina ; Tolley, William K. ; Hobson, Stephen T. ; Anderson, Ryan ; Fruhberger, Bernd
• 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 °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.
• Subjects:
  Benzene Graphite Nanocomposites Particle Size Polyvinyls Surface Properties Temperature Volatilization
• Keywords:
  Benzene Vapor Sensor Chemical Sensor Chemiresistor Exposure Monitor Graphene PEVA Polymer Nanocomposite Wearable Sensors
• Source:
  ACS Sens. 3(3):640-647
• Pubmed ID:
  29400061
• Pubmed Central ID:
  PMC5866224
• Document Type:
  Journal Article
• Funding:
  R43 OH010881/OH/NIOSH CDC HHSUnited States/
• Volume:
  3
• Issue:
  3
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha256:1f072eda26c89c8fe2f23935ae4e31e9307986f1bdb25f6ff07529c37bbb1c0f
• Download URL:
  https://stacks.cdc.gov/view/cdc/52778/cdc_52778_DS1.pdf
• File Type:
  [PDF - 2.43 MB ]