Single-walled carbon nanotube/Nafion composites as methanol sensors

The methanol concentration is the main factor influencing the electrical properties of the SWCNTs in methanol fuel. [Display omitted] ► SWCNT/Nafion composites is highly reliable and sensitive with methanol concentration. ► Swelling of Nafion is the only problem in higher concentration. ► The polar–polar interactions influence the electrical properties of the SWCNTs. Single-walled carbon nanotube (SWCNT)/Nafion composite films were fabricated on an interdigitated electrode by using a simple casting method. Nafion acts as a polymer backbone to give stable and homogeneous cast thin films. The potential use of the composites as sensors of methanol concentration in water was investigated. The composites are operative even at ambient temperatures, and respond quickly to concentration changes. The resistance increases significantly with increasing concentration between 0.5 M and 4 M. The composites may be useful as a material to measure the concentration of methanol for direct fuel cells.