Physical, optical and electrical properties of polyvinyl alcohol-graphene oxide nanocomposite films

In this article, polyvinyl alcohol (PVA) and polyvinyl alcohol-graphene oxide (PVA-GO) nanocomposites were prepared and characterized. The well-known solution-casting technique was used to develop nanocomposite samples. The optical, mechanical, structural, morphological, and electrical properties of PVA-GO nanocomposites were comprehensively studied in this work. It was found that adding nanofillers lowers the PVA's energy band gap. Meanwhile, absorption spectra from a UV–visible spectrophotometer are used to compute Urbach's energy, refractive index, extinction coefficient, real and imaginary dielectric constants, and optical conductivity. X-ray diffraction data clearly show a significant improvement in the crystallinity of nanocomposites with an increase in the GO fillers. The homogeneous distribution of GO in the PVA matrix was confirmed by the scanning electron microscopic pictures. Thermogravimetric measurements revealed that the nanocomposite films exhibited improved thermal stability. With the addition of GO to PVA, mechanical properties including tensile strength and Young's modulus were significantly enhanced. The dielectric permittivity studies revealed improvement in dielectric constant by increasing GO concentrations, due to interfacial polarization at lower frequency regions. The highest AC conductivity of 2.5 × 10^–4 S/cm is attained, demonstrating the good conductivity of PVA-GO nanocomposites.