Doping effect on self-assembled films of polyaniline and carbon nanotube applied as ammonia gas sensor

摘要

Here, composites based on carbon nanotubes and polyaniline films were tested as ammonia gas sensors with three different doping approaches (sulfuric acid, camphorsulfonic acid and m-cresol). The polyani line high sensitivity to ammonia combined with the stability of the carbon nanotube increased the sensors reproducibility when compared to a regular polyaniline. The sensor in which the doping was performed by camphorsulfonic acid, presented the best sensor response for ammonia gas (418%) when compared to the others. This result is addressed to the better polymer configuration achieved by this procedure. The device's operation in low concentrations of ammonia indicates a strong adsorption process whit a limit of detection of 4 ppm.