engleski

The influence of aniline-monomer and sulphuric acid concentrations on the morphology of polyaniline films.

The electrochemical synthesis of polyaniline (PANI) has been carried out by means of cyclic voltammetry. PANI film growth has been followed in dependence on aniline-monomer concentration, sulphuric acid concentration and on the switching potential (El) value. It is shown that all three variables influence the rate of PANI film growth. The resulting morphology of films has been examined by scanning electron microscopy (SEM). A very significant influence of acid concentration on the morphology of PANI film is established for the conditions of slow PANI film growth (lower El), since a "sponge"-like morphology obtained at lower acid concentrations, changes into crowded, gravel-like structures obtained from higher acid concentration (3 mole/dm3). SEM micrographs of PANI film samples obtained at higher El, which ensures a much faster supply of aniline-radical cations and consequently a faster film growth, assume slaggy appearance, the porosity of which decreases with the increase of acid concentration.

cyclic voltammetry; morphology; polyaniline; scanning electron microscopy (SEM)

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