Preparation and characterization of polyaniline (PANI)–Mn3O4 nanocomposite

Polyaniline (PANI)–Mn3O4 nanocomposite was synthesized by a combination of sonochemical synthesis of Mn3O4 NP's and in-situ polymerization of aniline. Structural characteristics were evaluated by XRD, FT-IR, TGA, VSM, TEM and SEM analysis, and conduction characteristics were evaluated by total conductivity measurements in the temperature range of 20–100 °C and frequency range of 0.1 Hz–1 MHz. Our findings show that PANI is successfully coated on nanoparticles surface and overall conductivity of nanocomposite is approximately 50–1000 times higher than that of uncapped Mn3O4 or PANI base with increase in temperature. Morphology of the synthesized powder was observed to be thin nanosheets with a thickness of 2–3 nm based on SEM analysis. Room temperature magnetization curves for nanocomposite show no hysteresis, indicating the super-paramagnetic character of the sample in the region of measured field strength. σAC increased after polyaniline coating.

Research highlights
► Polyaniline–Mn3O4 (PANI–Mn3O4) nanocomposite was prepared sonochemically by in-situ chemical oxidative polymerization of polyaniline in the presence of cetyl trimethyl ammonium bromide.
► The average crystallite size of nanocomposite was found to be 25.5±0.1 nm using the Scherrer's equation. Nanocomposite's overall conductivity is approximately 50–1000 times higher than that of uncapped Mn3O4 or PANI with increase in temperature.
► The absence of hysteresis curve for the product indicates the super-paramagnetic character in the region of measured field strength.