Molybdic acid doped polyaniline micro/nanostructures via a self-assembly process

Molybdic acid (H2MoO4, MA) doped polyaniline (PANI) micro/nanostructures were prepared by a self-assembly process in the presence of ammonium persulfate ((NH4)2S2O8, APS) as the oxidant. The morphology of PANI-MA changed from nanofibers or nanotubes (∼160 nm in diameter) to co-existence of nanofibers and microspheres (∼3 μm in diameter) and that accompanied an enhancement of the conductivity from 5.42 × 10−3 S cm−1 to 2.8 × 10−1 S cm−1as the molar ratio of MA to aniline varied from 0.01 to 1.5. With increasing the polymerization time, moreover, the pH value of the reaction solution not only decreased due to sulfuric acid produced during the course of the polymerization, but also accompanied a change in morphology from microspheres to nanofibers. All above-mentioned observations could be interpreted by spherical and cylindrical micelle composed of MA as the “soft-template” in forming the micro/nanostructures.