Development of QCM sensors based on MultiWalled Carbon Nanotubes -Poly(o-ethoxyaniline) Nanocomposites for the Detection of Volatile Organic Compounds

We synthesized the POEA-MWNTs nanocomposites by in situ chemical oxidative polymerization at different monomer/MWNTs weight ratios under standardized conditions and thin films were fabricated on the quartz crystal microbalance (QCM) electrode by Langmuir-Shaefer (LS) method. These sensing thin films materials were tested for very low concentration levels of benzene, toluene and xylene via nanogravometric method. Experimental data highlighted that the POEA-MWNTs nanocomposites showed a higher response than the pure conducting polymer, indicating that the sensor sensitivity was enhanced by optimizing the weight ratio of POEA and MWNTs. The selectivity of the sensor devices increased by varying the CNTs concentration used in the synthesis, due to the “tuning” of the physical chemistry properties of POEA-MWNTs nanocomposites involved in the absorption/desorption processes. Furthermore, the nanogravimetric sensors showed good reproducibility, sensitivity and rapid reversibility.