The fabrication of a MWNTs–polymer composite chemoresistive sensor array to discriminate between chemical toxic agents

In this study, a chemoresistive sensor was fabricated by the chemical polymerization and coating of either polyaniline (PANI), poly[2-methoxy-5-(2-ethyloxy)-p-phenylenevinylene], or commercial poly(methyl methacrylate) on MWNTs. We investigated the resistance responsiveness of the multilayer samples to simulated chemical warfare agents, including dimethyl methyl phosphonate (DMMP) and dichloromethane (DCM), as well as to organic agents, such as chloroform, tetrahydrofuran, methyl-ethyl ketone, and xylene. The MWNTs–PANI film was characterized by SEM and FT-IR, and the resistivity values for the six solvents were measured at different temperatures. We observed that the MWNTs-PANI sensing film exhibited a high sensitivity, excellent selectivity, and good reproducibility to the detection of all of the aforementioned agent vapors. In addition, we used atomic force microscopy to demonstrate the MWNTs–PANI absorption of DMMP vapor, wherein the sensing film exhibited a swelling phenomenon, such that the film thickness increased from 0.8 to 1.3 μm. In addition, we used principal component analysis to evaluate the performance of the sensor in detecting DMMP, DCM, and the aforementioned organic agent vapors.

[1]  S. Iijima.  Helical microtubules of graphitic carbon , 1991, Nature.

[2]  G. Anitha,et al.  Recognition and exposition of intermolecular interaction between CH2Cl2 and CHCl3 by conducting polyaniline materials , 2005 .

[3]  Peter J. F. Harris,et al.  Carbon Nanotubes and Related Structures: New Materials for the Twenty-first Century , 1999 .

[4]  Hidehito Nanto,et al.  Aroma identification using a quartz-resonator sensor in conjunction with pattern recognition , 1993 .

[5]  Bing R. Hsieh,et al.  Fluorescent conjugated polymer films as TNT chemosensors , 2004 .

[6]  Li Niu,et al.  A highly selective chemical gas sensor based on functionalization of multi-walled carbon nanotubes with poly(ethylene glycol) , 2007 .

[7]  Petra Pötschke,et al.  Conductivity spectroscopy on melt processed polypropylene–multiwalled carbon nanotube composites: Recovery after shear and crystallization , 2007 .

[8]  Radius and chirality dependent conformation of polymer molecule at nanotube interface. , 2006, Nano letters.

[9]  Jose Maria Kenny,et al.  Sensors for inorganic vapor detection based on carbon nanotubes and poly(o-anisidine) nanocomposite material , 2004 .

[10]  A. Vadivel Murugan,et al.  Electrochemically synthesised conducting polymeric materials for applications towards technology in electronics, optoelectronics and energy storage devices , 1999 .

[11]  M. Matsuguchi,et al.  Characterization of polymers for a capacitive-type humidity sensor based on water sorption behavior , 1998 .

[12]  T Okumura,et al.  Report on 640 victims of the Tokyo subway sarin attack. , 1996, Annals of emergency medicine.

[13]  T. Nakamoto,et al.  Perfume and flavour identification by odour-sensing system using quartz-resonator sensor array and neural-network pattern recognition☆ , 1993 .

[14]  Yen-Wen Lin,et al.  Doped polyaniline/multi-walled carbon nanotube composites: Preparation, characterization and properties , 2006 .

[15]  G. Shi,et al.  A water-soluble cationic oligopyrene derivative : Spectroscopic studies and sensing applications , 2009 .

[16]  J. Gardner.  Detection of vapours and odours from a multisensor array using pattern recognition Part 1. Principal component and cluster analysis , 1991 .

[17]  Duk-Dong Lee,et al.  Classification of chemical warfare agents using thick film gas sensor array , 2005 .