Synthesis and properties of high performance nanostructured polyaniline: Effect of initiator dosage and molecular oxygen

The effects of ammonium persulfate (APS)/aniline feed molar ratio or O2 bubbling on the polymerization of polyaniline (PANI) in self-stabilized dispersion polymerization (SSDP) were examined. As the APS/aniline feed molar ratio was increased from 0.25/1.00 to 1.50/2.00, the polymerization yield was enhanced from 20% to 80%. However the molecular weight reduction with increased feed ratio, that is normally observed when PANI was polymerized in aqueous medium, was little. The O2 bubbling during polymerization made the nanostructure of PANI to be finer, and this improved the solubility of PANI in solvent. The FT-IR spectra showed that the PANI prepared by SSDP, which have high conductivity in the range of 600–800 S/cm, contained less amount of the structures by ortho-coupling or Michael reductive addition of aniline compared to that synthesized by the standard method in an aqueous medium.