Fabrication of a novel PANI/[Co(NH₃)₄(C₃H₄N₂)₂]Cl₃ nanocomposite with enhanced dielectric constant and ac-conductivity

A new polyaniline/[Co(NH₃)₄(C₃H₄N₂)₂]Cl₃ nanocomposite was synthesised by in-situ oxidative polymerisation of aniline monomer in non-aqueous DMSO medium. The nanocomposite was investigated as a suitable material for energy storage and high frequency device applications due to its high value of dielectric constant (≈10⁴) and ac-conductivity (≈10⁸) with a rapid decrease in loss tangent in the high frequency region. The nanocomposite was characterised by techniques like UV–Vis spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction analysis and field emission scanning electron microscopy (FESEM). The results revealed presence of photoadduct (PA) in PANI@PA nanocomposite with significant interaction between PANI matrix and PA nanoparticles. The PANI@PA nanocomposite exhibit enhanced thermal stability broadening its scope of usability. The better dispersion of PA nanoparticles in the PANI matrix as observed in FESEM, facilitates better charge transport. Dielectric study showed capacitive effect of the nanocomposite at low frequency and a conductivity effect at high frequency. The high value of dielectric constant and ac-conductivity of PANI@PA nanocomposite is attributed to the heterogeneous structure of nanocomposite with enhanced interface, which has a positive effect on the dielectric properties of the material.