Preparation and characterization of conjugated PVA/PANi blend films doped with functionalized graphene for thermoelectric applications

Flexible nanocomposite thick films consisting of PVA_0.7PANi_0.3 polymer blend doped with different concentrations of nanoplatelets functionalized Graphene (NPFGx) (where x = 0, 5, 10, 15, 20, and 25 wt.%) were fabricated using the solution cast technique. Scanning electron microscopy (SEM), X-ray diffractometer (XRD), energy dispersive spectroscopy analysis (EDX), and Fourier-transform infrared spectra (FT-IR) were used to study the structure of the samples. The results showed that the ordered structure, its orientation, the PANis' well dispersion, and the electrostatic forces play a significant role in enhancing the interfaces between the polymer blend and the NPFG. Thermogravimetric analyses (TGA) and Thermoelectrical analyses (TE) showed that the PVA-PANi conducts a promised conjugated blend for thermoelectric applications. The introduction of the NPFG contents into the blend increased the TE measurements as the DC electrical conductivity ≈ 0.0114 (S cm⁻¹), power factor ≈ 3.93 × 10^–3 (W m⁻¹ K⁻²), and Z.T. ≈ 8.4 × 10^–7, for the 25 wt.% NPFG nanocomposite film. The effect of the polymers’ phonon contribution in the thermal conductivity controlling and enhancing the thermal stability of the prepared nanocomposite films.