Self-assembled polyaniline nanofibers/nanotubes

The result of a successful synthesis of the highly uniform, relatively long nanofibers-nanotubes of polyaniline through a self-assembly process assisted by the presence of excess oxidant ((NH4)2S2O8 ammonium persulfate, APS) without the use of any acid in the initial step was presented. The diameters of nanofibers/nanotubes described are based on multiple TEM measurements with statistical analyses in different areas. Besides the relatively long nanofibers/nanotubes, a few micro-/nanospheres and granular/flake-like particulates appear in the product. This might result from the decreasing pH during the synthesis. After purification and redoping by 1 M HCl(aq), doped polyaniline nanostructures present the characteristic absorption bands of emeraldine salt. Excess APS initiator rapidly induces the formation of dimer cation-radicals (dimer surfactant) before polymerization resulting in the increase of the surfactant concentration in an aqueous solution.