VAPOUR SENSING PROPERTIES OF CARBON NANOTUBES ONTO CADMIUM ARACHIDATE MULTILAYER INVESTIGATED BY ACOUSTIC SENSORS AND OPTICAL FIBRE BASED REFLECTOMETER SENSOR

摘要

We investigate the sensing properties of the single-walled carbon nanotubes deposited onto cadmium arachidate buffer multilayer by acoustic oscillating sensors – 315, 433 MHz SAW and 10 MHz QCM - and an optoelectronic sensor based on optical fiber reflectometry for VOCs detection, at room temperature. The carbon nanotubes are deposited by the Langmuir-Blodgett technique. The acoustic and optical sensors have been simultaneously exposed, in the same test cell, to individual VOCs of ethanol, methanol, iso-propanol, acetone, ethylacetate, toluene with different vapour pressures for comparing the sensitivity of the carbon nanotubes onto the several kinds of the sensors. For each transducer used, the effect of carbon nanotubes onto the gas sensitivity is remarkably higher. Pattern recognition based on PCA has been successfully applied for VOCs recognition using multisensors with complementary transducing principles.