A superhydrophilic nitinol shape memory alloy with enhanced anti-biofouling and anti-corrosion properties

Abstract

This work reports on a nitinol (NiTi) surface modification scheme based on a chemical oxidation method, and characterizes its effects on wetting, biofouling and corrosion. The scheme developed is also compared with selected previous oxidation methods. The proposed method turns NiTi into superhydrophilic in similar to 5 min, and the static contact angle and contact angle hysteresis were measured to be similar to 7 degrees and similar to 12 degrees, respectively. In the PRP (platelet rich plasma) test, platelet adhesion was reduced by similar to 89% and similar to 77% respectively, compared with the original NiTi and the NiTi treated with the previous chemical oxidation scheme. The method developed provides a high (similar to 1.1 V) breakdown voltage, which surpasses the ASTM standard for intervascular medical devices. It also provides higher superhydrophilicity, hemo-compatibility and anti-corrosion resistance than previous oxidation schemes, with a significantly reduced process time (similar to 5 min), and will help the development of high performance NiTi devices.