Poly (vinyl alcohol) hydrogel (PVA-H) is expected to be a suitable artificial articular cartilage material because of its high biocompatibility. However, it is difficult to affix to the surface of a living joint because it is bioinert and its mechanical strength needs to be improved. In this study, graphene oxide (GO) subjected to two oxidation rounds was used to form a nanocomposite material and the composite hydrogel PVA-GO-H was prepared by low-temperature crystallization. Scanning electron microscope (SEM) images showed that the addition of GO can increase roughness of the hydrogel surface. Contact angle measurements showed that the surface of PVA-GO-H exhibited hydrophobicity that increased with GO concentration and not with that of PVA-H, indicating that the hydrophilic parts of PVA and GO form hydrogen bonds and the hydrophobic part of GO was exposed on the surface. Tensile tests demonstrated that Young’s modulus was enhanced on the addition of GO. Osteoblast cells showed more affinity for PVA-GO-H than PVA-H, which much more cells adhere to than to PVA-GO-H after a certain period of culturing, suggesting GO can improve the cell attachment of PVA-H. Further studies on the influence of the oxidation time of GO are still required.

In order to determine the molecular interaction to improve the mechanical properties of graphene oxide (GO)–epoxy resin composites, we investigated the relationship between GO oxidation properties and the tensile strength of the epoxy resin.