Polypyrrole-Titania Nanocomposites Derived from Different Oxidants

Polypyrrole(PPy)/titania(TiO 2 ) nanocomposites were prepared by an in situ oxidative polymerization method with two different oxidants, namely ammonium persulfate (APS) and ferric chloride. The effects of oxidant type and TiO 2 particle loading level on the physiochemical properties of the PPy/TiO 2 nanocomposites were investigated in details. The intermolecular interactions within the polymer nanocomposites were explored by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). While scanning electron microscopy (SEM) was used to characterize surface morphology, transmission electron microscopy (TEM) revealed the well-dispersed TiO 2 nanoparticles in the PPy matrix. The thermogravimetric analysis (TGA) revealed improved thermal stability of PPy with addition of the nanofillers. The nanocomposites prepared by APS oxidation exhibited lower electrical conductivity at room temperature than that of the PPy nanocomposites from FeCl 3 oxidation polymerization. Both nanocomposites and pure PPy follow the three-dimensional variable range hopping (VRH) electron conduction mechanism. The frequency dependent dielectric constants of PPy/TiO 2 nanocomposites were measured in the range of 20 Hz–2 MHz.