【作者】 王志浩；

【导师】 冷永祥；

【作者基本信息】 西南交通大学 ， 材料学， 2007， 硕士

【摘要】 血管支架已经被广泛的应用于冠心病的介入治疗，但是血管支架的再狭窄问题一直是比较难解决的问题，并影响着血管支架在临床应用上的前景。血栓的形成可能是引起发生再狭窄的原因之一，目前的药物洗脱支架很难解决晚期血栓的发生，前期研究表明Ti-O薄膜具有优良的血液相容性，应用于血管支架表面可以防止血管支架植入后急性或亚急性血栓的形成，但Ti-O薄膜存在着比较脆、结合力差的缺点，在支架撑开时比较容易断裂而从支架脱落形成局部腐蚀点，从而使Ti-O薄膜失去了对支架的保护功能。Ti-O薄膜的良好血液相容性与其表面性质有关，但材料与血液的作用机理尚不明确，有待进一步研究。本文采用非平衡磁控溅射法在316L不锈钢拉伸试样上沉积了Ti-O薄膜，利用拉伸试验研究了沉积温度、基体偏压、薄膜厚度、过渡层对薄膜在不锈钢表面结合力的影响。拉伸试验表明，400℃沉积的薄膜的结合力要好于在200℃和50℃沉积的薄膜；在50V偏压下沉积的Ti-O薄膜的结合力要好于在150V偏压下制备的薄膜；88nm厚的Ti-O薄膜的结合力要好于270nm厚的薄膜；添加Ti过渡层的Ti-O薄膜的结合力要好于没有Ti过渡层的薄膜。采用非平衡磁控溅射法在316L不锈钢血管支架表面制备Ti以及TiO₂薄膜，初步研究了Ti薄膜厚度、TiO₂薄膜沉积速率对薄膜在血管支架表面附着状况的影响。结果表明，支架变形后，不锈钢支架表面薄的Ti薄膜附着状况比厚的Ti薄膜好；在低沉积速率下制备的TiO₂薄膜在血管支架表面附着状况好于高沉积速率时制备的TiO₂薄膜；对于Ti/TiO₂复合薄膜，Ti层厚度增大不利于Ti/TiO₂复合薄膜在不锈钢支架表面附着。采用直流反应非平衡磁控溅射技术，以O₂和N₂的混合气体为反应气体，通过改变O₂和N₂的比例，获得了不同结构、成分和性能的Ti-O-N薄膜。随着反应气体中N₂含量的增加，薄膜的结构从锐钛矿和金红石相，依次变为Ti₃O₅和锐钛矿相、Ti₃O₅单相，最后变为TiN。Ti-O-N薄膜中的N元素含量随着反应气体中N₂比例的增加而增加，薄膜中的N原子主要以取代晶格位置O原子的形式存在，有少量的固溶N₂，表面还有少量分子吸附N₂。Ti-O-N薄膜的方块电阻和禁带宽度随薄膜中N元素含量的增加而下降，方块电阻由大于2000千欧降到0.141千欧，禁带宽度从3.17eV降到1.5eV。在紫外辐照后Ti-O-N薄膜的水接触角均有不同程度的降低，没有掺杂N和掺杂量较少的TiO₂薄膜接触角降低幅度大于N含量较大的Ti-O-N薄膜。紫外辐照后Ti-O-N薄膜的表面能都有所提高，极性分量急剧增加，极性分量与色散分量的比值也从辐照前的0.1～0.2增加到1.0～1.6。紫外辐照后接触角逐渐回升，辐照后7小时内回升速率较快，7小时后趋于稳定。血小板黏附试验结果表明Ti-O-N薄膜的血液相容性与TiO₂薄膜相比较差。紫外辐照后1小时内Ti-O-N薄膜的血液相容性有较大改善，随着时间的延长，Ti-O-N薄膜的血液相容性逐渐变差。更多还原

【Abstract】 Vascular stents are widely used in intervention treatment, and stents implantation became a standard surgery of coronary angioplasty. However, in-stent restenosis introduced by tissue hyperplasia and thrombosis is the major problem in clinic application. Drug-eluting stents have been reported that thrombosis was formed in months after implantation.Stent coated with thin film can resolve the thrombosis problem. But bad adhesion is an obstacle to thin film for being applied on the surface modification of stent. And the reactive mechanism between biomaterials and blood is still unclear until now.In this paper, Ti-O films were deposited by unbalanced magnetron sputtering. Adhesion of Ti-O films on 316L stainless steel substrate was investigated by tensile test. The results indicate that adhesion of TiO₂ film is better than adhesion of TiO film. The adhesion of the Ti-O film deposited at 400℃is better than those deposited at 50℃and 200℃. The adhesion of Ti-O film applied 50V bias voltage is better than the one applied 150V bias voltage. Thickness of films affects its adhesion on substrate. The adhesion of the 88nm thick Ti-O film is better than the 270nm thick one. Ti interlayer can improve adhesion of Ti-O film on stainless steel substrate. The adhesion of the Ti-O film with Ti interlayer is better than the one without Ti interlayer. The investigation of TiO₂ adhesion on the surface of vascular stents indicates that the adhesion of the thinner Ti film is better than that of the thicker films. The result indicates that the adhesion of the TiO₂ film fabricated at lower deposition rate is better than the one deposited at higher deposition rate. The adhesion of the films decreased as the Ti interlayer thickness increasing.In this paper, Ti-O-N films with different structures and compositions were synthesized on silicon wafer by reactive unbalanced magnetron sputtering. By controlling the proportion of N₂ in the reactive gas （O₂+N₂）, Ti-O-N films with different structures, composites, properties and blood compatibilities were obtained. With increasing proportion of N₂, the structure of Ti-O-N film changes from anatase and rutile to Ti₃O₅, finally to TiN. XPS results reveal that the content of nitrogen in the films increased with increasing proportion of N₂. The band gap and the sheet resistance of Ti-O-N films decreased with the increasing content of nitrogen inside Ti-O-N films. After ultraviolet radiation of two hours, water contact angle of Ti-O-N films decreases and the surface energy increases. The blood compatibility of Ti-O-N films is worse than TiO₂ film. After ultraviolet radiation of two hours, the blood compatibility of Ti-O-N films is obviously improved.更多还原