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Indexed by:期刊论文

Date of Publication:2010-05-06

Journal:JOURNAL OF PHYSICAL CHEMISTRY C

Included Journals:SCIE、EI、Scopus

Volume:114

Issue:17

Page Number:7986-7994

ISSN No.:1932-7447

Abstract:Dimethylmethylphosphonate (DMMP) is a simulant for the highly toxic organophosphate nerve agent Sarin (GB). The influence of DMMP on the ionic conductivity of zeolite Y is investigated by impedance spectroscopy. In the presence of 20-100 ppm of DMMP, the ionic conductivity of the sodium exchanged form of the zeolite showed an increase. The interaction between DMMP and the zeolite was elucidated by examining different cation-exchanged zeolites as well as external surface modification with ceria to deactivate acidic groups. A mechanism involving the binding of the sodium cation with the phosphonate group of DMMP that results in facilitated inter cage motion of the cation is proposed. The change in impedance measured at a single frequency of 3000 Hz allows for the use of Na(+)-exchanged zeolite Y as a sensor for detecting ppm level of DMMP. Sensing data were obtained over a temperature range of 300-350 degrees C, with best results at 320 degrees C. This device exhibited minimal response to CO, NH(3), methane, and propane, possible interferents in the ambient air.