【作者】 刘华；

【导师】 崔春翔；

【作者基本信息】 河北工业大学 ， 材料学， 2004， 硕士

【摘要】 生物相容性是钛基生物医用材料研究中应首先考虑的重要问题之一。为了提高材料的生物相容性，本研究对自制的钛基体进行了二氧化钛涂层的制备和表面碱液生物活化处理的研究，并采用模拟体液培养实验和细胞培养实验评价了表面改性后材料的生物相容性和生物活性，对基体以及表面改性后材料的组织形貌、相组成和生物相容性进行了观察、分析与评估。 采用非自耗真空电弧凝壳炉熔炼钛及钛合金，并对钛合金的组织及性能进行观察和测定，分析了电弧炉熔炼钛合金的结晶特点。实验中选用的合金元素有Mo、Nb、Zr、Fe等，均为β稳定元素。 钛及其合金具有良好的抗蚀性和生物相容性与其表面的氧化膜ZiO₂有关，基于此，采用不同工作介质条件制备了二氧化钛涂层。本研究采用包埋烧结法分别在常压和真空条件下在钛合金试样上制备二氧化钛功能涂层，并对涂层的表面形貌和相组成进行了分析。发现制备的二氧化钛功能涂层中晶粒尺寸为微米级，晶型主要为金红石型二氧化钛，表面粗糙度值大小不一。 涂层的表面粗糙度对于材料的生物活性有直接影响。为了改变涂层表面的粗糙度，实验中从改变涂层粉末的粒度入手，以钛酸丁酯为原料，通过醇盐水解法制备了纳米级锐钛矿型TiO₂超细粉，粒径约为5～10nm，而普通二氧化钛粉体的粒径多在100nm左右。用纳米二氧化钛粉包埋钛合金试样烧结制备的涂层表面粗糙度值Ra在2.1～2.3μ m之间，相对于普通二氧化钛粉包埋烧结的涂层来说，粗糙度较低。纳米二氧化钛涂层的晶粒直径在50nm～70nm之间，偶有小于50nm的小晶粒。 除了在钛合金表面制备涂层外，还尝试了对钛合金基体表面直接采用碱液处理的方法进行表面生物活化。具体为运用统计学原理，在不同温度下（60℃～100℃）用不同浓度（5M～10M）的氢氧化钠溶液处理不同的钛合金基体，以确定最佳的生物活化处理条件。 利用模拟体液培养实验对表面改性后材料的生物相容性和生物活性进行了评估。在培养相同的时间后，发现纳米TiO₂／Ti合金沉积磷灰石的能力最强。不同表面改性方法的SBF培养结果比较为：纳米二氧化钛涂层＞碱液处理方法＞常压下烧结二氧化钛涂层＞真空下烧结制备的涂层。 对纳米二氧化钛／钛合金生物材料进行细胞培养实验，发现该材料具有良好的细胞相容性。更多还原

【Abstract】 Biocompatibility is one of the most considerable problems in the study of Ti matrix biomedical material. In order to improve titanium alloy’s biocompatibility, the titanium dioxide coating was fabricated on Ti matrix. Besides, the surface of titanium alloys was directly disposed by alkali to make it possess bioactivity. Biocompatibility and bioactivity of the material after surface modification were evaluated through the simulated body fluid (SBF) cultivation and cell cultivation experiment. Surface morphology, phase constitution and biocompatibility of the material were analyzed and evaluated in this paper.Titanium alloys were prepared by non-consumable vacuum arc smelting furnace. And the microstructures and the properties of titanium alloys were investigated. The structure character of cast titanium alloys was studied. The alloy elements selected in this experiment were Mo, Nb, Zr and Fe, which were β stable elements.The excellent resist erosion and biocompatibility of pure titanium and titanium alloys are attributed to the TiO2 film on the surface. So the titanium dioxide coatings were fabricated by cladding substrates to sinter in different work mediums, which included normal pressure and vacuum conditions. The surface morphology and phase constitution of coatings were analyzed. The results indicated that the crystal particles in coatings were mostly rutile, and the size of the rutile was in a micrometer grade. The surface roughness of coatings was different.Surface roughness of coatings affects the bioacitivity of materials, In order to change the roughness of coatings, the granularity of coating powders was changed firstly. Nanometeral anatase titanium dioxide powders were prepared by hydrolysis of titanium-tetrabutoxide with ethanol in this paper. The main particle size is between 5nm and 10nm, while the size of ordinary titanium dioxide powders is about 100nm. The nanoparticles coating was fabricated by cladding titanium alloys with nano-TiO2 powders, and its surface roughness was 2.1-2.3 μ m which was smaller than that of ordinary titanium dioxide coatings. The diameter of crystal particle in nano-coatings is mainly between 50nm and 100nm, and sometimes less than 50nm.In addition to fabricate coatings on the surface of titanium alloys, the bioactivities on thesurface of titanium alloy substrates were done by alkali solution. Making use of statistical principle, the different Ti substrates were dealt with in different temperatures(60℃~100℃) by different concentrations(5M~10 M) NaOH solutions so that we can confirm the most appropriate technique.Biocompatibility and bioactivity of the material after surface modification were evaluated through the simulated body fluid cultivation experiment. After cultivated for same days, the capability of Ca phosphates deposition of nano-TiO2/Ti alloys was the best. The SBF cultivation results by different surface modification methods were: nano-TiO2 coating > alkali solution treatment > TiO2 coatings sintered in normal pressure > TiO2 coatings sintered in vacuum.The nano-TiO2/Ti alloys possessed favorable cell compatibility testified by the cell cultivation experiment.更多还原