CLATHRATES AS COATING MATERIALS FOR DIELECTRIC TRANSDUCERS WITH REGARD TO ORGANIC-SOLVENT VAPOR SENSORS

The interdigitated capacitor using 2,2'-bis(9-hydroxy-9-fluorenyl)biph enyl (1) as inclusion host, embedded in a polymer matrix (polyvinyl ch loride with a plasticizer) as coating material, shows a sensitivity to organic solvent vapours, The sensitivity depends on the host compound contents in the membrane. The best results have been obtained for the PVC membrane containing 27% 1 and 57% 2-fluorophenyl 2 2-nitrophenyl ether as plasticizer. The sensor demonstrates reproducible, reversible responses with a response time of 1-2 min when exposed to vapours of dichloromethane and tetrachloroethylene with concentrations in the ran ge 0.05-3.5 vol.%, while being about 10 times more sensitive to tetrac hloroethylene.