Preparation of high-yield polyaniline nanofibers via an unstirred polymerization

Abstract Polyaniline nanofibers with high yield (93%) have been synthesized by an unstirred polymerization of aniline in aqueous acid media with ammonium persulfate as an oxidant in the absence of any template, dopant or surfactant. The morphology, structure and electrical conductivity of the nanostructural polyaniline prepared under different conditions were characterized by means of scanning electron microscopy, FTIR, UV-vis and four-probe techniques. It was found that branched network-like polyaniline nanofibers were prepared without any mechanical stirring, whereas irregular and rodlike structural polyaniline samples were obtained with mechanical stirring under the same reaction conditions. Flowerlike polyaniline microspheres of ca. 3.5 μm in outer diameter, which were constructed with nanostructural polyaniline lamellar by self-assembly process, were synthesized during the polymerization at 0 °C for 72 h. The as-synthesized HCldoped polyaniline nanofibers have good room-temperature electrical conductivity of 5.0 S/cm.