Detection of explosives and nitro-substituted aromatic molecules with metal oxide sensors

CHED 1618

Justin Kreil, jkreil81@gmail.com, Department of Chemistry, Austin Peay State University, Clarkville, TN 37044 and Gregory J. Szulczewski, gjs@bama.ua.edu, Department of Chemistry, The University of Alabama, 250 Hackberry Lane, Box 870336, Tuscaloosa, AL 35487.
The change in resistance of SnO2 and WO3 films upon exposure to the vapors of various nitroaromatic compounds was measured between 150-400°C in air. The molecules examined were m-dinitrobenzene, 4-nitrobenzenethiol, 4-nitrobenzaldehyde, 4-nitrobenzoic acid, 1-nitropyazole, 2,4-dinitrotoluene, and 2,4,6-trinitrotoluene (TNT). In general, the resistance of the SnO2 and WO3 films decreased (by ~ 50-100%) upon initial adsorption, except for 1-nitropyrazole. The recovery time for the sensors was one to three minutes at all temperatures tested. A mechanism is proposed to explain the resistance changes. Using these metal oxide films, as little as 5ppb TNT in air could be detected.

This work was supported by the National Science Foundation through the Research Experience for Undergraduates program (grant # CHE 0647789).

 

General Papers
1:00 PM-3:40 PM, Thursday, April 10, 2008 Hilton New Orleans Riverside -- HEC A, Oral

Division of Chemical Education

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008