Conductive Polymer-Based Transducers as Vapor-Phase Detectors

Publisher Summary This chapter discusses the development of conductive polymer-based transducers for the detection of volatile organic compounds (VOCs) and other gaseous pollutants for application in environmental monitoring. In the experiment described in the chapter, highly sensitive sensor elements derived from polyaniline (PANI) are demonstrated for NO 2 and other VOCs. A figure of merit is defined to allow the comparison of the response of different sensors to particular challenge vapors at various concentrations. The use of excess silane coupling agents to modify the surface of the sensor substrates in combination with excess of a sulfonic acid used to convert PANI to its conductive state results in highly sensitive, stable, and reversible VOC sensors, along with some polythiophene derivatives, for the detection of ketones, esters, and aromatic hydrocarbons. Individual sensors show different sensitivities to each class of VOC used in the study so that an array of these sensors generated a characteristic signature for each class demonstrating selectivity and classification.