Gas sensing materials from carbon black/poly(methyl methacrylate) composites

In this work, the electrical conductivity of carbon black/poly(methyl methacrylate) composites and its responsiveness to organic solvent vapors were investigated. The carbon black-polymer conducting composites were synthesized by in-situ polymerization. They exhibited a low electrical percolation threshold (similar to3.3wt% of carbon black). The electric resistance of the composites increased drastically by over 10(4) times when they were exposed to good solvent vapours such as chloroform, tetrahydrafuran and ethyl acetate, and it recovered when the composites were transferred to air. The effect of temperature on the vapour responsivity of the composites was notable. An elevated temperature accelerated the vapour-induced variation in electrical resistance of the composites. The experimental data also indicate that the composites possessed a good reproducibility of vapour responsivity. These results suggest that they can be regarded as promising gas sensors characterized by easy processability and cost effectiveness.