When the mole ratio of ammonium peroxydisulfate to aniline is 1:1 to 2:1

polyaniline which is synthesized chemically has a high yield and conductivity. When ammonium peroxydisulfate is present in more excess

it leads to marked decrease in the conductivity of polyaniline. This is due to the fact that ammonium peroxydisulfate is a strong oxidizing agent

which oxidizes various intermediate to produce different products and causes further oxidation of polyaniline. Although various oxidizing agents can raise the electrode potentials of sam-ples of polyaniline. their conductivities and electrochemical activities decrease markedly.This is caused by the further oxidation of polyaniline. In order to maintain a high electrochemical activity of polyaniline

common presence of polyaniline and strong oxidizing agents should be avoided.