Synthesis and characterization of polyaniline/calcium oxide compozites and preparation of conductive films

In this study, the inherently conductive polymer polyaniline was synthesized using an optimized process to produce polyaniline/calcium oxides (PANI/CaO) composites by in-situ polymerization and ex-situ solution mixing. PANI and PANI/CaO composite films were prepared by drop-by-drop and spin-coating methods. The electrical conductivities of HCl doped PANI film and PANI/CaO composite films were measured according to the standard four-point-probe technique. The composite films exhibited an increase in electrical conductivity over neat PANI. The increase of conductivity of PANI/CaO composites may be partially due to the doping or impurity effect of CaO, where the CaO particles compete with chloride ions. PANI and PANI/CaO composites were investigated by spectroscopic methods including UV-Vis, FT-IR and photoluminescence. UV-Vis and FT-IR studies showed that CaO particles affect the quinoid units along the polymer backbone and indicate strong interactions between CaO particles and quinoidal sites of PANI. The photoluminescence properties of PANI and PANI/CaO composites were studied and the photoluminescence intensity of PANI/CaO composites was higher than that of neat PANI. The amount of weight loss and the thermostability of PANI and PANI/CaO composites were determined from thermogravimetric analysis. The morphology of particles and films were examined by a scanning electron microscope (SEM). SEM measurements indicated that the CaO particles were well dispersed and isolated in composite films.