Characterization of Graphene Oxide Composites in a Matrix of High and Low Molecular Weight Polyvinyl Alcohol

Graphene oxide (GO) has been combined with polyvinyl alcohol (PVA) to make composite films with improved properties such as high tensile strength, increased optical conductivity and high refractive index. Different methods of processing GO/PVA composites have led to reduction in GO resulting in improvements of electrical conductivity of the films. Films prepared on glass substrates using high molecular weight PVA demonstrated an electrical conductivity that increased with the GO concentration. However, these films appeared porous and had poor adhesion to the substrate. When low molecular weight PVA was used as the matrix material, the GO composites showed improved film properties resulting in uniform and coherent films. However, these films demonstrated an electrical conductivity that was lower compared to the ones prepared with high molecular weight PVA. Therefore, various combinations of low and high molecular weight PVA at different ratios were investigated to optimize electrical conductivity and film properties. Mixtures of high- and low-molecular weight PVA/GO films resulted in higher electrical conductivity after subjecting to thermal processing. Resistance readings were taken in fixed width strips to calculate the resistivity and conductivity. ATR-FTIR data revealed the transformation of functional groups in optimized films. These optimized GO/PVA films may find usage in energy storage systems, solar cells, and other electronic applications.