PLASTICIZED POLYMERIC ELECTROLYTES - NEW EXTREMELY VERSATILE RECEPTORMATERIALS FOR GAS SENSORS (VOC MONITORING) AND ELECTRONIC NOSES (ODORIDENTIFICATION DISCRIMINATION)/

A new class of receptor materials for gas sensors for volatile organic compounds (VOC) was developed: plasticised polymeric electrolytes (PP E). A PPE usually consists of three components: a polymer; a plasticis er; and an organic salt. In an extensive systematic study more than 50 0 compositions using seven polymers, eight plasticisers and four organ ic salts were tested in order to investigate the effect of individual components and their ratio on the gas sensing properties (selectivity, sensitivity, etc.) of the PPE. The operation of a PPE-based gas senso r is based on a variation of the bulk ionic conductivity of the recept or layer due to absorption of an ambient vapour. The specific conducta nce of the used PPE compositions is usually between 0.1 and 10 mu S x cm(-1) and it may vary more than 100 times in the dynamic range of the gas sensor, which stretches typically from low ppm up to some 10000 p pm. The PPE-based gas sensors using miniaturised interdigitated transd ucers demonstrate a remarkable variety of their properties depending o n the PPE composition. The performance of single sensors and sensor ar rays was thoroughly studied. (C) 1998 Elsevier Science S.A. All rights reserved.