氧化处理对医用镍钛合金表面亲水性的影响

Objective To evaluate the effect of oxidation on the hydrophilic property of the medical nickel titanium（ NiTi） alloy. Methods The test samples were divided into two groups as a oxidized group and a non-oxidized group. NiTi alloy with nearly equiatomic ratio of nickel and titanium elements was selective oxidized in boiled 30% hydrogen peroxide solution solution. Then, the oxidized alloy was ultrasonically rinsed with deionized water and dried at 37 ℃. Static contact angle was measured using contact angle measuring instrument by stop drop method. The samples were placed in the sample room. Deionized water and α -bromonaphthalene were dropped on the samples surface. Then the measured pictures were acquired and the contact was evaluated by the accompanying software. Results The surface contact and interfacial tension of the oxidized NiTi alloy was lower than those of the non-oxidized while the surface tension was higher. The blood compatibility of the NiTi alloy will be improved by surface oxidation concerning wetting ability, interfacial tension and surface tension. Conclusion Surface thermodynamics properties including wetting ability, surface tension and interfacial tension are improved by oxidation treatment which leads to the improvement of blood compatibility of the NiTi alloy.