VOCs vapour sensor based on polyaniline salts films and quartz crystal microbalance.

摘要

A sensor based on the quartz crystal microbalance (QCM) technique was used for the detection of a number of organic volatile compounds (VOCs) vapours such as aromatics, alcohols and amphoteric solvents. Detection was mainly based on sensitive and thin films of synthesized polyaniline, emeraldine salt (ES), doped with three different dopants (HCI, DBSA and NDSA) prepared by dip coating of a QCM electrode. Values of the frequency shifts (Δf) were found to be linearly correlated with the (VOCs) concentration given in part per million (ppm). The changes in the frequency are principally due to the establishment of electrostatic interaction developed between the ES films and sorbents as well as the sorbent type. The sensitivity of the sensor was found to be governed by the dopant type and the thickness of the prepared thin layer. The sensor .has shown a good reproducibility and reversibility.