Study of structural, optical, dielectric properties poly-3-butyl thiophene reinforced with Co3O4 nanoparticles

The alignment and orientation of the fillers in a polymer matrix play an important role in the dielectric properties of composite materials. In the present research work, Co3O4 nanoparticles (NPs) (3, 8 wt%) were dispersed over poly-3-butyl thiophene (P3BT) by microwave irradiation. The hybrid nanocomposite (HNC) films were fabricated by the solution casting technique. The structural, morphological, thermal and optical properties of the HNC were analysed using various analytical techniques. A granular morphology was observed with agglomerations as the concentration of the Co3O4 NPs was increased on P3BT matrix and the grain size decreased from 32 to 22 nm. A redshift in the optical absorbance resulted with a decrease in the direct optical band gap (Eg) from 2.75 to 2.60 eV, while the indirect band gap decreased from 2.23 to 2.20 eV with an increase in the concentration of the Co3O4 NPs. Thermogravimetric analysis (TGA) showed that P3BT/Co3O4 (3, 8 wt%) HNC possesses higher stability, up to 500 °C, than the pure P3BT polymer. A significant increase in the specific surface area (246–396 cm2/g) and pore volume (0.76–0.98 cm3/g) resulted with the increase in the concentration of the Co3O4 NPs on the P3BT polymer. The dielectric properties of P3BT/Co3O4 (3, 8 wt%) HNC at different temperatures (40–140 °C) showed a significant improvement in the dielectric constant (ɛ) with minimal dielectric loss (tan δ). The dielectric constant (ɛ) for P3BT/ Co3O4 (8 wt%) HNC at 140 °C (100 Hz) was four times higher than the dielectric constant of the pure P3BT polymer. The synthesized HNC is a useful material for sensors, piezoelectric and photosensitive applications.