A sensor of alcohol vapours based on thin polyaniline base film and quartz crystal microbalance

• Published in: Journal of hazardous materials 2009-08, Vol.168 (1), p.85-88
• Main Authors: Ayad, Mohamad M., El-Hefnawey, Gad, Torad, Nagy L.
• Format: Article
• Language: English
• Subjects: Adsorption; Air Pollutants - analysis; Alcohol; Alcohols - analysis; Aniline Compounds - chemistry; Applied sciences; Chemical engineering; Diffusion; Electrochemical Techniques - instrumentation; Electrochemical Techniques - methods; Exact sciences and technology; Gases - analysis; Pollution; Polyaniline base; Quartz crystal microbalance; Reproducibility of Results; Vapour sensor
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2009.02.003

Thin films of polyaniline base, emeraldine base (EB), coating on the quartz crystal microbalance (QCM) electrode were used as a sensitive layer for the detection of a number of primary aliphatic alcohols such as ethanol, methanol, 2-propanol and 1-propanol vapours. The frequency shifts (Δ f) of the QCM were increased due to the vapour adsorption into the EB film. Δ f were found to be linearly correlated with the concentrations of alcohols vapour in part per million (ppm). The sensitivity of the sensor was found to be governed by the chemical structure of the alcohol. The sensor shows a good reproducibility and reversibility. The diffusions of different alcohols vapour were studied and the diffusion coefficients ( D) were calculated. It is concluded that the diffusion of the vapours into the EB film follows Fickian kinetics.