Petrol vapours sensor with polyvinyl trimethylsilane sensitive coating

Abstract A quartz crystal microbalance sensor for determining petrol vapours in ambient air has been developed. Polyvinyl trimethylsilane (PVTMS) was used as a sensitive coating. The influence of the polymer coating mass on the performance characteristics of the sensor was studied. The optimal mass of the PVTMS film was found, at which the signal-to-noise ratio was maximum. On the basis of the frequency-time characteristics measured, the kinetics of adsorption and desorption processes were studied and the responses of the sensor and recovery times were found. The sorption of petrol hydrocarbons on PVTMS was fully reversible. The dependences of the response of the sensor on the concentration of petrol vapours showed good linearity in the range of 50 – 1250 ppm. The limit of detection was estimated to be 25 ppm. It was found that the sensor exhibits a high selectivity in the presence of water vapour in the relative humidity range of 0 – 50%.