Effects of Electro-Fenton Process on Blood Compatibility and Nickel Suppression of NiTi Shape Memory Alloy

Electro-Fenton process as a modified Fenton’s oxidation method in waster water treatment can provide a stable hydroxyl radical (·OH) source by continuous reaction of electrochemically generated H2O2 with Fe2+ ions for surface oxidation modification of NiTi shape memory alloy (SMA). In this work, effects of electro-Fenton process on blood compatibility and nickel suppression of NiTi SMA were investigated by SEM and XPS, inductively-coupled plasma mass spectrometry (ICPMS), hemolysis analysis and blood platelet adhesion test. It is found that electro-Fenton process is a notably effective way to impede out-diffusion of Ni from NiTi SMA in simulated body fluids during the entire ten week immersion period. It can also improve the hemolysis resistance and thromboresistance of biomedical NiTi SMA. The improvement of blood compatibility and nickel suppression of NiTi SMA can be attributed to the formation of surface titania film with a Ni-free zone near its top surface by electro-Fenton process.