Fabrication of MWNTs-PANI composite - a chemiresistive sensor material for the detection of explosive gases

A chemiresistive sensor was fabricated by the chemical modification of multi-walled carbon nanotubes (MWNTs) and chemical oxidation of polyaniline (PANI). The resistances of the sensing film samples against 100, 250, 500, 1000 ppm explosives (picric acid (PA), 2,6-dinitrotoluene (2,6-DNT) and 2,4,6-trinitrotoluene(TNT)) agents were investigated. The MWNTs with various wt. % PANI agents were characterized by TGA, SEM, FTIR and Raman spectroscopy, respectively. The experimental results showed that 1wt. % MWNTs and 10, 5, 1wt. % PANI sensor samples provided high sensitivity, excellent selectivity and good reproducibility to PA and 2,6-DNT vapours. In addition, principal component analysis (PCA) was applied to distinguish the performance of PA, 2,6-DNT and TNT agents. Our results indicate that the electric detection of explosive agents is possible with simply fabricated MWNTs–PANI devices.