Graphene enhanced anti-corrosion and biocompatibility of NiTi alloy

Abstract Due to their unique shape memory effect and superelasticity, NiTi shape memory alloys have been considered for a wide range of biomedical applications. However, they are still controversial because of the potential toxic, carcinogenic and allergic effects caused by Ni 2 + release for a long term use. Wrapping protective layers with good flexibility and biocompatibility is significant for inhibiting the poisonous Ni 2 + releasing from NiTi. Here, we report a novel method to protect the NiTi and enhance its biocompatibility by using graphene fabricated via a modified chemical vapour deposition (CVD) technique. The graphene layer not only prevents effectively the leak of Ni 2 + but also improves the biocompatibility of NiTi upon deformation. The detailed mechanism for enhancing the anti-corrosion and biocompatibility of NiTi alloy by using graphene is also explored. Compared with traditional surface modification layer, graphene obtained by CVD is chemically inert and highly flexible, possesses both good anti-corrosion and biocompatibility properties, which may improve the surface coatings for NiTi alloys and promote more application of graphene in biomedical materials.