One-Pot Synthesis and Electrical Characterization of Monodisperse Solid Polyaniline Sub-Microspheres

Monodisperse solid polyaniline (PANI) sub-microspheres were synthesized in nonpolar solvent toluene using chloroaurate acid (HAuCl₄) as the oxidant and cetyltrimethylammonium bromide (CTAB) as the phase-transfer reagent. The reduction of chloroaurate acid is accompanied by oxidative polymerization of aniline, leading to the formation of uniform solid PANI sub-microspheres covered with a breadcrumb-like structure, with a diameter of about 400 nm and incorporated with gold nanoparticle aggregates. The resulting solid PANI sub-microspheres were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, UV-visible spectroscopy, and X-ray diffraction (XRD). The formation mechanism of the solid spheres is also discussed. The current–voltage (I–V) characteristics of the PANI submicrospheres were measured, which indicate the conductivity of the samples is related to the degree of doping which is pressure dependent.