Comparative Study on Structural, Dielectric Behavior and AC Conductivity of PPY-PVA Incorporated with TiO₂ Fine and Nano Particles

An In situ oxidative chemical polymerization technique was used to prepare thin films of PPY, PVA, and PPY-PVA blend doped with variable concentrations of TiO 2 fine- and nano-particles further investigated by X-ray diffractometer (XRD) and impedance spectrometer to study structural, dielectric, and AC conducting behavior. XRD spectra established that sharp and high intense peaks of PPY-PVA- fine TiO 2 films indicated more crystallinity, which might be due to higher compactness and modification in interplanar spacing. Dielectric plots revealed that PPY-PVA-nano TiO 2 films exhibited higher dielectric constants and lower dielectric loss compared to films of PPY-PVA- fine TiO 2 in shorter frequency region, suggesting that these films are more suitable for charge storage devices. Conductivity plots revealed that AC conductivity of pure PPY was low (4.8 × 10 −3 S cm −1 at 313 0 K) and was increased to 5.3 × 10 −3 S cm −1 by addition of PVA. AC conductivities of PPY-PVA-nano TiO 2 thin films are relatively higher (7.43 × 10 −3 S cm −1 to 1.14 × 10 −2 S cm −1 ) than PPY-PVA-fine TiO 2 films (6.35 × 10 −3 to 9.78 × 10 −3 S cm −1 ) with increasing frequency and temperature, which could be due to large surface area to volume ratio of nano-size dopant. This suggests that PPY-PVA-nano TiO 2 thin films may be used for sensing various gasses.