Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7144147 | Sensors and Actuators B: Chemical | 2016 | 24 Pages |
Abstract
We report the time resolved pulsed photoacoustic (PA) spectra of different types of solid carbon blacks obtained from wood charcoal; graphite powder and diesel soot using 532Â nm wavelength pulses of duration 30Â ps at a repetition rate of 10Â Hz. The result of the PA spectra allows us to evaluate the potential use of graphite powder for the identification of trinitrotoluene (TNT) explosive for the first time. Though, TNT has no absorption band at 532Â nm (due to higher band gap i.e. 2.7Â eV), but its mixture in graphite matrix might reduce the band gap and enable it to absorb 532Â nm wavelength due to pi-orbital coupling between graphite and TNT molecules. This is clearly observed concerning downshift in the Raman spectra of the mixture. Further, it is also explained using momentum exchange mechanism due to acoustic phonon waves in their common bands of Raman spectra. Finally, we have studied the different weight percentage of TNT explosive to generalize the response of PA signal.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
K.S. Rao, A.K. Chaudhary, F. Yehya,