On the sensitivity of conductimetric acetone gas sensor based on polypyrrole and polyaniline conducting polymers

Polypyrrole (PPy) and polyaniline (PANi) synthesized onto the Au/Al2O3 by chemical oxidation-casting (COC), chemical vapor deposition (CVD) and impregnated oxidation (IO) techniques are employed to monitor the level of acetone in gas phase. With PPy prepared by CVD (PPy(CVD)) as the sensing material, the sensitivity of acetone gas sensor is found to be 5.20 × 10−7 ppm−1. The sensitivity of acetone gas sensor based on PANi is greater than that of PPy. The maximum sensitivity and minimum response time are obtained for PANi prepared by IO technique. With PANi(IO)/Au/Al2O3 as the sensing electrode, the sensitivity, response and recovery times of acetone gas sensor are 5.908 × 10−4 ppm−1, 1.0-3.0 and 3.0-10.0 min, respectively. The detection limit of acetone gas sensor based on PANi(IO) is 29 ppm.