We have investigated the use of spin-coated thin films of polyaniline (PANI) doped with organic acids in conductive gas and vapour sensors operating at room temperature. Its advantages are discussed with respect to other organic conductors and inorganic metal oxides operating at much higher temperature. We have carried out experiments with test devices based on films of either doped PANI or its mixtures with cis-1,4-polybutadiene, polystyrene, polyphenilacetilene and polyammide (Nylon6). The additional polymers have been used in order to tune selectivity to different gaseous species and vapours and to improve processability by spin-coating and wettability on glass substrates and on metal and ITO electrodes. Good adhesion and uniformity have been so obtained. In addition to sensitivity to alcohol and water vapours, we report a very strong increase in the resistivity as a response, in seconds to minutes time scale, to gas pollutants such as ammonia and nitrogen oxides in the ppm concentration range. This variation appears to be reversible even at room temperature and can be significantly sped up by heating the sample to 40-50 °C.
Preparation of polyaniline conductive composites with diene-rubber or polyphenylacetylene suitable for gas-sensing
R Beccherelli;
2001
Abstract
We have investigated the use of spin-coated thin films of polyaniline (PANI) doped with organic acids in conductive gas and vapour sensors operating at room temperature. Its advantages are discussed with respect to other organic conductors and inorganic metal oxides operating at much higher temperature. We have carried out experiments with test devices based on films of either doped PANI or its mixtures with cis-1,4-polybutadiene, polystyrene, polyphenilacetilene and polyammide (Nylon6). The additional polymers have been used in order to tune selectivity to different gaseous species and vapours and to improve processability by spin-coating and wettability on glass substrates and on metal and ITO electrodes. Good adhesion and uniformity have been so obtained. In addition to sensitivity to alcohol and water vapours, we report a very strong increase in the resistivity as a response, in seconds to minutes time scale, to gas pollutants such as ammonia and nitrogen oxides in the ppm concentration range. This variation appears to be reversible even at room temperature and can be significantly sped up by heating the sample to 40-50 °C.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
