Electrochemical synthesis of polyaniline in reverse microemulsion

The electro-polymerization behavior of aniline in reverse（W/O） microemulsion was investigated. The experiment results show that the cyclic voltammetry polymerization behavior of aniline in W/O microemulsion is different from that in aqueous solution remarkably. With the increase of scan cycle, the oxidation potential shifts positively and the reduction potential shifts negatively, i.e., the redox potential difference increases. H＋ apparent concentration affects the aniline polymerization evidently. When H＋ concentration is lower than 0.08 mol/L, the electro-polymerization of aniline is difficult. With the increase of H＋ concentration, the polymerization current of aniline increases gradually. Only when H＋ concentration is high enough（0.5 mol/L）, aniline can be well electro-polymerized. Moreover, under the same condition, the aniline polymerization current in W/O microemulsion is higher than that in aqueous solution. The scanning electron microscopy image shows that the deposited polyaniline（PANI） has uniform fiber morphology with diameter of about 100 nm. Further study result suggests that the electrochemical activity of the PANI in HCl is similar to that of the PANI prepared in aqueous solution.