A series of polyaniline films have been coated on electrodes by chemic
al and electrochemical means in order to investigate the thermal stabi
lity of the electroactivity in air and nitrogen atmospheres. Polyanili
ne was also synthesized chemically and cast as a membrane (thick film)
. It was found that the electroactivity and conductivity of the films
was stable up to 150 degrees C. Exposure to higher temperatures leads
to a decrease in electroactivity and conductivity, although use of a n
itrogen atmosphere had less effect on the properties. Thermogravimetri
c analysis profiles confirmed that the polymer was stable to above 350
degrees C. The changes in the electroactivity may be attributed to mo
rphological (annealing) effects in the polymer and to loss of moisture
and dopant ions.