Synthesis and characterization of a conducting polyaniline/TiO₂−SiO₂ composites

Abstract

ABSTRACT Polyaniline/TiO 2 −SiO 2 composites were prepared by an in situ chemical oxidation polymerization approach in the presence of hybrid TiO 2 −SiO 2 fillers. The obtained polyaniline/TiO 2 −SiO 2 composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectrometer (FTIR), X‐ray diffraction (XRD), thermogravimetry (TG), and current−voltage (I−V) measurements. SEM picture shows a variation in morphology of polyaniline (PANI) from fiber shape to relatively regular particle shape with increasing TiO 2 −SiO 2 contents in the composites. The floccule‐like structures were observed by high resolution TEM, which may help improve the efficiency of conductive network. SEM, XRD, TG, and FTIR spectra all reveal that a relatively strong interaction exist between TiO 2 −SiO 2 and PANI. The I−V characteristics in such composites indicate that the charge transport is mainly governed by the space charge effects, which occurs at the interface between the conducting PANI and TiO 2 −SiO 2 . Meanwhile, PANI/TiO 2 −SiO 2 composites exhibit significant increase in conductivity than PANI/TiO 2 or PANI/SiO 2 . The reasons about high conductivity of PANI/TiO 2 −SiO 2 have also been discussed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2288–2295, 2013