Facile Synthesis of Hierarchical Polyaniline Nanostructures with Dendritic Nanofibers as Scaffolds

Hierarchical polyaniline nanostructures with branched nanofibers as scaffolds are prepared by a solution method using ferric chloride oxidant without using any organic structure directing reagent or hard template. The synthesis parameters, such as reaction temperature and time, on the morphologies and crystal structures of polyaniline nanomaterials have been investigated. After 24 h of polymerization at 25 degrees C, the surfaces of polyaniline dendritic nanofibers are decorated with polyaniline nanorods with diameters of 5-20 nm. Increasing the reaction temperature to 60 degrees C, the polyaniline nanofibers become smoother, longer, and thinner. XRD, TGA, FTIR, and UV-vis analyses confirm that the products are emeraldine salts with good crystallinity. Also, the product polymerized at 60 degrees C yields higher thermal stability but lower doping level than that fabricated at 25 degrees C, which may be caused by the higher content of the phenazine-like segment in the product. The growth process has been discussed.