Application of Cobalt Phthalocyanine, Polyaniline and their Blend of Nano Scale Thick Film as Chemical Gas Sensors

Chemical gas sensing behavior of cobalt phthalocyanine (CoPc), polyaniline emeraldine base (Pani-EB) and nano films obtained by blending them was studied. Sandwich configurations of Metal-Polymer-Metal obtained on well cleaned glass substrate were employed. The bottom and top metal (Au) electrodes were deposited by vacuum evaporation technique and the middle polymer layer was deposited by spin coating method. The response to ammonia, carbon-dioxide, methane and acetone gases was studied at room temperature. From the observations, it is seen that the sensing behavior of Pani-EB, CoPc and CoPc/Pani-EB blend films is good with a quick recovery for acetone vapor and CO₂ gas. For ammonia, the sensing behavior is good but the recovery is very poor. In the case of methane gas, Pani-EB and CoPc/Pani-EB blend show good sensing behavior and the recovery is also very quick. The response of CoPc to methane gas is not impressive