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Previously made experimental results indicate that PNCC composite material electric resistance increases remarkably, when the composite is exposed to organic solvents vapour (OSV). PNCC composition was: matrix material – polyisoprene; filler – 10 mass parts of carbon black nanoparticles (PRINTEX XE2 specific surface 950 m2/g, mean diameter of primary particles 25 nm, DBP absorption 380 ml/100g)). PNCC electric resistance increase can be described as follows: when the composite is exposed to OSV, molecules of vapour adsorbs on the surface of PNCC and diffuse into the composite matrix, distance between aggregates made by carbon black nanoparticlles increases, tunnelling currents between carbon aggregates decreases and composites electric resistance increases. The composite is tested to 10 different OSV, results are reported elsewhere [1]. These results were obtained using bulk-nanostructured composite material with dimensions: 50 x 5 x 1(0,4; 0,3; 0,2) mm. Elaborating miniature PNCC composite material we obtain several benefits: (i) increased composite material response to volatile analyte, (ii) reduced electric resistance relaxation time (iii) PNCC can sense lower OSV concentrations limits and (iv) much easily completing of the samples into electronic detection device. From electric resistance measurements with miniature PNCC sample we observed exponential electric resistance response increase versus time (instead of linear increase us for bulk PNCC samples) and saturation of relative electric resistance change at the final of measurements (Fig 1). |
