Abstract:Polyaniline (PAn) was prepared by chemical oxidation polymerization and characterized by FT-IR. PAn/SnO₂ materials with different mass fractions of PAn were prepared by mechanical mixing. Compared with single PAn and SnO₂, the gas sensitivity of PAn/SnO₂ materials to volatile organic compounds (VOCs, methanol, ethanol and acetone) was studied. The possible response mechanism of PAn/SnO₂ materials to VOCs was also discussed. It is found that PAn/SnO₂ materials have gas sensitivity to VOCs at 90 ℃ among the four operating temperatures (room temperature, 30, 60 and 90 ℃), but PAn and SnO₂ have no gas sensitivity at the above temperatures. The sensitivity of PAn/SnO₂ materials shows linear increase with the increase of methanol concentration, but saturation with the increase of ethanol and acetone concentrations. PAn/SnO₂ materials have high selectivity, fast response-recovery time and low operation temperature to VOCs, but pure PAn and SnO₂ do not have.

Key words: gas sensitivity; polyaniline/SnO₂; volatile organic compounds