Conducting polymer gas sensors part II: response of polypyrrole to methanol vapour

Abstract Conducting films of polypyrrole deposited across a narrow gap between two gold electrodes can be used to sense methanol vapour by following changes in the resistance of the polymer. The response is rapid and reversible at room temperature. The effects of the concentration of methanol, the operating temperature and the film thickness on the response have been investigated. The data are consistent with a model in which the methanol interacts with sites either on, or within, the polymer. Simple gas sensors of this type are promising candidates for use in an ‘intelligent’ gas sensor based on an array of gas-sensing elements.