H₂SO₄ doped polyaniline films were synthesized in aqueous acidic media. The polyaniline film deposited on platinum electrode exhibits highest conductivity. The conductivity of each H₂SO₄ doped polyaniline sample was determined by the four-probe technique. The current–voltage curve exhibits that polyaniline sample has an ohmic behaviour. Experiments were conducted to establish the conductivity of the sample from room temperature to 110°C. The current was set constant. It has been observed that at lower current as well as higher current conductivity of the polyaniline sample is due to the electrons transferred to the conduction band. It is observed that the concentration ratio of 0.2 : 1 of aniline and H₂SO₄ for synthesis of PANI film on platinum electrode shows good conductivity.

The potentiometric study of polyaniline (PANI) film synthesized with dopants viz. polyvinyl sulfonic acid (PVS), 𝑝-toluene sulfonic acid (𝑝TS), dodecyl benzene sulfonic acid (DBS) and composite-dopants viz. PVS–𝑝TS and PVS–DBS, has been carried out. The synthesized PANI films were characterized by electrochemical technique, UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and conductivity measurement. It was found that the PANI doped with PVS gives good electrochemical properties, conductivity as well as surface morphology as compared to 𝑝TS and DBS, whereas in composite dopants the PANI doped with PVS–𝑝TS gives good polymer matrix as compared to PVS–DBS.