To cite this article: Mustapa, R., Abu Mansor, Z. I. & Sambasevam, K. P. (2018). Fabrication of polyaniline based chemical sensor for ammonia gas detection. J. Phys. Sci., 29(Supp. 1), 9–16, https://doi.org/10.21315/jps2018.29.s1.2
Polyaniline (PAni) is one of the versatile conducting polymers due to inexpensive monomer, environmental benign, high conductivity and easy preparation. In this study, PAni was doped by dioctyl sulfosuccinate sodium (AOT) to enhance the processability of PAni in gas sensor detection. PAni/AOT was synthesised via in-situ polymerisation at 0°C for 24 h in the presence of potassium peroxydisulfate (KPS). The characterisations were done by Fourier transform infrared (FTIR) and ultravioletvisible (UV-Vis). FTIR spectra depict the main characteristic peaks of PAni/AOT at 1550 cm−1 and 1455 cm−1 which indicates quinoid and benzoid units, respectively. The presence of AOT dopant was confirmed by observing the peak at 1731 cm−1. UV-Vis spectra further confirmed the PAni/AOT is in the doped state by exhibiting a characteristic peak at ~800 nm. Sensor performance of PAni/AOT film was studied in terms of selectivity, long term stability and method validation. It was found that, PAni/AOT exhibited stability up to 1 week. Besides that, PAni/AOT film also exhibited good selectivity for NH3 in the presence of common interfering species such as hexane, diethyl ether and acetone gas. In conclusion, PAni/AOT was successfully prepared for NH3 detection. The limit of detection of PAni/AOT was ~11ppm.