Polyaniline nanofibers prepared with hydrogen peroxide as oxidant

Polyaniline (PANI) nanofibers were successfully prepared by a sonochemical way with hydrogen peroxide as the oxidant. In comparison with the polymerization performed with mechanical stirring, the polymerization rate of aniline was greatly enhanced and PANI nanofibers were achieved instead of the particulate PANI, though the yield was decreased relatively, indicating the positive effect of ultrasound in producing PANI nanostructures. The uniformity and lengths of the PANI nanofibers were greatly improved as compared with the PANI nanofibers synthesized with ammonium peroxydisulfate (APS) as oxidant under the same conditions, rendering hydrogen peroxide a better oxidant in producing high-quality PANI nanofibers. The PANI nanofibers exhibited similar FTIR spectra, XRD patterns, and dispersibility, but different UV-vis spectra, to their counterpart synthesized with APS as oxidant. UV-vis spectra showed only the head-to-tail structured PANI molecules were produced in the high-quality PANI nanofibers. The findings will be of some help to elucidation of the formation mechanism of PANI nanofibers.