密度泛函理论研究鸟氨酸盐在Mg(0001)表面的吸附机理

Density functional theory study of the adsorption mechanism of ornithine salt on the Mg( 0001) surface

镁及镁合金具有与人体自然骨的密度相近,良好的生物相容性等特点,但作为生物医用材料植入人体之后,及易降解和腐蚀.本论文用密度泛函理论研究了鸟氨酸盐在Mg(0001)表面的吸附,通过吸附能,态密度,电荷差分密度等分析发现鸟氨酸盐在Mg(0001)表面存在强烈的Mg-O和Mg-N相互作用,从而鸟氨酸盐有望在镁金属的表面可以形成一层致密的氧化膜,达到改善镁金属材料的耐腐蚀性,降低降解速度的目的 .

Magnesium （Mg） and its alloys have the characteristics of similar density to human natural bones and the excellent biocompatibility. However, it is easy to degrade and corrode after implanting into the human body as biomedical materials. In this paper, we investigated the adsorption of ornithine （Orn） salt on the Mg（0001 ） surface using the density functional theory （DFT）. It is found that there are strong Mg- 0 and Mg -N interac- tions between Orn and Mg（0001 ） surfaces through analyzing the adsorption energies, density of states （DOS）, charge difference density etc. Therefore, Orn salt is expected to form a layer dense oxidation film on the Mg and its alloys surfaces, and then to reach the aims of the larger corrosion resistance and the lower degradation speed.