Conjugated polymer/multi-wall carbon nanotubes composite based volatile organic compounds sensors

Abstract

Polyimidazole multi-walled carbon nanotubes (Plm/MWCNTs) nanocomposite films were synthesised by chemical oxidation of imidazole monomer and addition of MWCNTs to the conductive polymer (CP) solution in a 1:1 ratio. The sensing performance of the Plm/MWCNTs nanocomposite films was measured by recording their electrical response when exposed to contrasting mixtures of gas. Generally, the nanocomposite film with a diameter of 3-12 nm shows a fluctuating response of their resistance when exposed to the analyte together with an excellent sensitivity of 90%. The response is quantified as the fractional change in resistance compared to the baseline, R₀ , i.e., the response ratio S = ΔR/R₀ . Values of S in the range 0.60–1.5 were observed for volatile organic compounds. This research work provides a simple, economical and environmentally-friendly technique to create favourable Plm/MWCNTs composite based volatile organic compounds sensors, which could be employed for environmental monitoring in workable electronic devices in domestic and industrial applications. The research findings established that Plm/MWCNTs nanocomposites have promising future applications in gas sensing.