The mechanisms of passive dissolution of titanium in a model physiological environment.
The mechanisms of passive dissolution of titanium in a model physiological environment.
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钛在模型生理环境中被动溶解的机制。
DOI：
10.1002/jbm.820260305
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Ducheyne,P
中科院分区：
文献类型：
--
作者：
Healy,KE;Ducheyne,P
测量钛的表面化学、氧化和溶解动力学，以建立在生理环境中被动溶解的机制。将钛薄膜浸入模拟间隙电解质（EDTA/SIE）中的8.0 mM乙二胺-四乙酸中，并在37 ° C、10% O2、5% CO2和7.2 pH下保持长达3200 h（133天）的时间段。采用两种浸泡方案：积分顺序测定释放到累积溶解产物溶液中的钛;微分连续补充试验溶液。通过双极原子吸收光谱法（EAAS）分析溶液中的钛，并通过俄歇电子能谱法（AES）和X射线光电子能谱法（XPS）分析样品表面以确定氧化物组成、化学计量和厚度。浸泡前两种类型的羟基（OH）基团上的TiO 2表面上区分。浸泡后，表面的化学变化作为浸泡的函数：OH基团的存在增加和P（非元素）在表面检测。溶解动力学符合两相对数模型，其中相之间的转变与含P物种的吸附同时发生。溶解动力学依赖于表面反应，电场强度，和分子扩散。这些机制解释了所观察到的表面氧化物和溶液配体的性质上的溶解动力学的依赖性。
The surface chemistry, oxidation, and dissolution kinetics of titanium were measured to establish the mechanisms of passive dissolution in physiological environments. Titanium thin films were immersed in 8.0 mM ethylenediamine‐ tetraacetic acid in simulated interstitial electrolyte (EDTA/SIE) and maintained at 37°C, 10% O2, 5% CO2and 7.2 pH for periods of time up to 3200 h (133 days). Two immersion schemes were employed: the integral sequentially determined the titanium released into a solution of accumulated dissolution products; and the differential continuously replenished the test solution. The solutions were analyzed for titanium by electrothermal atomic absorption spectrometry (EAAS), and the sample surfaces were analyzed by Auger electron spectroscopy (AES) and x‐ray photoelectron spectroscopy (XPS) to determine oxide composition, stoichiometry, and thickness. Prior to immersion two types of hydroxyl (OH) groups were distinguished on the TiO2surface. Upon immersion, the chemistry of the surface changed as a function of immersion: the presence of OH groups increased and P (nonelemental) was detected at the surface. The dissolution kinetics obeyed a two‐phase logarithmic model, where the transition between phases occurred simultaneously with the adsorption of the P‐containing species. The dissolution kinetics depended on surface reactions, electric field strength, and molecular diffusion. These mechanisms explain the observed dependence of dissolution kinetics on the properties of the surface oxide and solution ligands.