Conducting Polyaniline-Titanium Dioxide Nanocomposites Prepared by Inverted Emulsion Polymerization

Conducting polyaniline (PAni)-titanium dioxide (TiO2) nanocomposites have been synthesized by the inverted emulsion polymerization method. Aqueous mixtures of aniline, a free-radical oxidant, and/or TiO2 nanoparticles (similar to 25 nm in diameter; mixture of anatase and rutile) are utilized to synthesize the hybrid nanocomposites. The polymerization is carried out in an organic solvent (chloroform, CHCl3) in the presence of a protonic acid (hydrochloric acid, HCl) as a dopant and an emulsifier (cetyl trimethylammonium bromide). The resultant PAni-TiO2 nanocomposites are characterized with their structural, morphological, conducting, and optical properties. SEM and TEM images represent the PAni-TiO2 nanocomposites with the diameter range of 50-200 nm. Electrical conductivities are checked by standard four-point probes method and found to be 0.38 S/cm for bulk PAni and 0.11 S/cm for PAni-TiO2 nanocomposites. UV-visible absorption shows two electronic bands at about 320 and 596 nm for bulk PAni and the blue-shifted bands with the intensity changes due to the formation of PAni-TiO2 composites. Thermogravimetric analysis reveals that the composites have a higher degradation temperature than the PAni alone. POLYM. COMPOS., 31:83-88, 2010. (C) 2009 Society of Plastics Engineers