High performance hybrid composite conductive films: development towards smart materials for gas sensor applications

Abstract

Polymer composite thin film used for gas sensor applications with a new type of conductive filler called “carbon aerogel” in a polydimethylsiloxane (PDMS) matrix was fabricated and characterized. The resistivity changes of the composite films when exposed to different analytes, viz. tetrahydrofuran, acetone and methanol, were investigated. It is found that different types of polybenzoxazines, used as organic precursors for carbon aerogel preparation have no significant effect on the response of the sensor to the analytes. Compared with commercially available graphite/PDMS composites, the carbon aerogel/PDMS composites show better gas responsitivity. By mixing only 8 wt% of our carbon aerogel, the percolation threshold is obtained while as much as 30 wt% of graphite, normally used as a conductive filler, is required to attain the percolation threshold.