Study the Sensitivity of Quartz Crystal Microbalance (QCM) Sensor Coated with Different Thickness of Polyaniline for Determination Vapors of Ether, Chloroform, Carbon tetrachloride and Ethyl acetate

A quartz crystal microbalance (QCM) sensor coated with a thin film of polyaniline was used as a sensitive method for the determination of a number of following vapours: Ether, Chloroform, Carbon tetrachloride and Ethyl acetate. The detection was based on the absorption of the vapours of these organic compounds into the film by using gas cell chamber. The detection of these vapours can be obtained in part per million (ppm). The work includes the use of polyaniline films with different thickness (55, 82, 102 and 153) nm where thickness of the PANI films was controlled by the spin coating process. Results show that increasing of sensitivity with increase of the concentration of injected analyte when the PANI-film-coated QCM was exposed to the vapours of ethanol, propanol hexane and benzene. Best sensitivity to ethanol and hexane were obtained with film thicknesses 93nm while in the case of propanol best results were obtained with thickness of 118 and 93 nm. Thickness of 93 and 176 nm gave good sensitivity to benzene. Keywords: QCM, Polyaniline, Vapors, Sensor, Thickness