Characterization of the Temporal Response Profile of Carbon Black−Polymer Composite Detectors to Volatile Organic Vapors
- Creators
- Briglin, Shawn M.
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Lewis, Nathan S.
Abstract
The relative differential resistance responses of carbon black−poly(ethylene-co-vinyl acetate) (PEVA) composite vapor detectors were evaluated in response to short rise time (<2 ms for a 17 ms pulse length) square pulses of acetone, n-hexane, methanol, 2-propanol, or toluene, in a background of synthetic air. The use of ultrathin films, along with a rapid vapor delivery system, facilitated measurement of the rapid time response available from this exemplary carbon black−polymer composite chemiresistive film for the detection of common organic vapors. Detectors formed from very thin (<200 nm) PEVA−carbon black composites produced steady-state responses within 17 ms upon exposure to methanol and produced steady-state responses within 90 ms upon exposure to toluene, acetone, and n-hexane. In accord with Fickian diffusion, the response times of the relative differential resistance of PEVA−carbon black detectors to analyte exposures were proportional to the square of the film thickness, l, in the range 510 ≤ l ≤ 5700 nm. Additionally, the relative differential resistance versus time profiles of PEVA−carbon black detectors were well fit by a simple finite difference model based on Fickian analyte diffusion, using a single analyte diffusion coefficient, for a variety of different film thicknesses and analyte concentrations.
Additional Information
© 2003 American Chemical Society. Received: February 18, 2003; In Final Form: May 20, 2003. Publication Date (Web): September 16, 2003. We acknowledge the NIH and an Army MURI for support of this work.Attached Files
Supplemental Material - jp030218i_s.pdf
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Additional details
- Eprint ID
- 77419
- DOI
- 10.1021/jp030218i
- Resolver ID
- CaltechAUTHORS:20170512-133726724
- NIH
- Army Research Office (ARO)
- Created
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2017-05-12Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field