Resistive sensors for organic vapors based on nanostructured and chemically modified polyanilines

Abstract

Resistive sensors for organic vapors were made usingpolyaniline (PANI) and functionalized PANI as thin films ordeposits of PANI nanofibers. PANI thin films were synthesized byin situ chemical polymerization onto flat polyethylene films. PANInanofibers were produced by interfacial polymerization. Bothpolymeric materials were chemically modified through aromaticelectrophilic substitution or nucleophilic addition and used asactive materials in resistive sensors. The analysis of the resistancetimesensor profiles suggested that chemical modification affectsstrongly the sensor response. Moreover, the magnitude, the sign,and the rate of the sensor response showed differences for activematerials with the same chemical structure and differentmorphology. It is demonstrated that using only one conductingpolymer but creating material diversity by chemicalfunctionalization or morphological changes different sensorsresponses for the same volatiles can be obtained. This behaviorallows a simple way to produce sensors arrays which can be usedin electronic noses.