离子束合成TiO_2薄膜对医用NiTi合金表面的改性

SURFACE MODIFICATION OF BIOMEDICAL NiTi ALLOY BY ION BEAM SYNTHESIZING TiO_2 FILM

采用离子束增强沉积法制备ＴｉＯ２薄膜，对医用ＮｉＴｉ合金进行表面改性处理．系统研究了薄膜的表面组成、结构、形貌及耐蚀性、亲水性等与血液相容性相关的表面性质．ＮｉＴｉ合金表面沉积ＴｉＯ２薄膜后、抗模拟体液的腐蚀性提高，凝血时间延长．为进一步提高ＴｉＯ２薄膜的抗凝血性，对ＴｉＯ２薄膜的进一步表面改性－表面结合肝素分子进行了初步尝试，结果表明，薄膜表面组成发生变化，表面亲水性进一步提高。

TiO2 film on the surface of NiTi alloy was synthesized by using ion beam enhanced deposition (lBED). Surface composition, structure and surface morphology as well as the corrosion resistance and hydrophilia of the film, which were correlated with blood compatibility intimately, were investigated. The corrosion resistance and blood compatibility of NiTi alloy were improved after coating with TiO2 film on the surface. In order to further improve the anticoagulation of TiO2 film, heparin molecule was attached on TiO2 film surface. The results showed that N, S, which come from heparin molecule, were present on the surface, and the other components of Ols (532.9 eV and 531.9 eV) became prominent after modification, indicating that the amount of C-O and -OH components increased. The contact angle measurement showed that TiO2 film is hydrophilic, and the hydrophilia was further improved after attaching heparin molecule.