Abstract
Novel gas sensors based on functionalized multi-wall carbon nanotubes (MWCNTs) were fabricated and characterized with alcohols and their mixtures. MWCNTs (Multi-walled-carbon-nanotubes) were first functionalized by acid treatment and were then dispersed in PVA solution. The solution was then transferred into Teflon tubes to fabricate CNT foams by freeze-drying. The sensors were capable of distinguishing water and different alcohols at saturated pressure and their mixtures of varying concentrations. The operating mechanisms for the fabricated sensors were proposed, wherein correlations between the sensitivity of the sensor and the product of the molecular polarity and vapor pressure of different vapors were established and experimentally demonstrated.