Strong reduced graphene oxide-polymer composites: hydrogels and wires

By in situ chemical reduction of graphite oxide (GO) mixed with poly(vinyl alcohol) (PVA), we successfully fabricated reduced graphene oxide (rGO)-PVA composite hydrogels with improved dispersion and load transfer in their composites. The rGO-PVA composite wires were made by thermal-drawing or by directly drawing from the rGO-PVA dispersion and their mechanical properties were rapidly evaluated using a microfabricated tuning fork device. It was found that the Young's modulus of the polymer composites increase by ca. 200% with only 0.68 vol % addition of the rGO. The thermal properties of the composites were studied by differential scanning calorimetry (DSC), and it was observed that the addition of graphene to PVA greatly improves the thermal stability of the composites. Raman spectroscopy revealed the existence of an interaction between the graphene and the polymer via the shift in the vibration bands of the graphene in the composites.