Multifunctional conductive polypyrrole nanocomposites

Two novel conductive polymer nanocomposites have been fabricated and studied for potential electronics industry applications: PPy/SiC nanocomposites and PPy/TiO2 nanocomposites. Conductive polypyrrole nanocomposites are fabricated via a facile oxidative polymerization approach using p-toluene sulfonic acid as a dopant. The effects of the nanoparticles loading, ratio of oxidant to monomers, and nanoparticle morphology (spheres and rods) on the physicochemical properties are investigated. Various characterization methods are carried out to determine the material properties. Thermal gravimetric analysis demonstrates an improved thermal stability of polypyrrole in the polymer nanocomposites (PNCs) with a higher decomposition temperature. Powder X-ray diffraction analysis demonstrates the crystallinity of polypyrrole and poor crystallinity is observed for the PNCs with higher nanoparticle loading. The electron transport in PNCs follows a quasi 3-d variable range hopping conduction mechanism as evidenced by the temperature-dependent conductivity function. Experimental results demonstrate that PPy nanocomposites have higher conductivity than that of the pure PPy. A Transmission Electron Microscope (TEM) image of the nanocomposite revealed well-dispersed TiO2 particles in the PPy matrix. Conductivity of PPy/TiO2 nanocomposites oxidized by FeCl3 has a higher conductivity than the PPy/TiO2 nanocomposites oxidized by APS which may be from the lower oxidation/reduction potential of FeCl3.