Objective

The presence of metallic species around failed implants raises concerns about the stability of titanium alloy (Ti-6Al-4V). Graphene nanocoating on titanium alloy (GN) has promising anti-corrosion properties, but its long-term protective potential and structural stability remains unknown. The objective was to determine GN’s anti-corrosion potential and stability over time.

Methods

GN and uncoated titanium alloy (Control) were challenged with a highly acidic fluorinated corrosive medium (pH 2.0) for up to 240 days. The samples were periodically tested using potentiodynamic polarization curves, electrochemical impedance spectroscopy and inductively coupled plasma-atomic emission spectroscopy (elemental release). The integrity of samples was determined using Raman spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy and scanning electron microscopy. Statistical analyses were performed with one-sample t-test, paired t-test and one-way ANOVA with Tukey post-hoc test with a pre-set significance level of 5%.

Results

There was negligible corrosion and elemental loss on GN. After 240 days of corrosion challenge, the corrosion rate and roughness increased by two and twelve times for the Control whereas remained unchanged for GN. The nanocoating presented remarkably high structural integrity and coverage area (>98%) at all time points tested.

Significance

Graphene nanocoating protects titanium alloy from corrosion and dissolution over a long period while maintaining high structural integrity. This coating has promising potential for persistent protection of titanium and potentially other metallic alloys against corrosion.

中文翻译：

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石墨烯纳米涂层为钛合金提供卓越的持久腐蚀保护

客观的

失败的植入物周围金属物质的存在引起了对钛合金 (Ti-6Al-4V) 稳定性的担忧。钛合金（GN）上的石墨烯纳米涂层具有良好的防腐性能，但其长期保护潜力和结构稳定性仍然未知。目的是确定 GN 的抗腐蚀潜力和稳定性。

方法

GN 和无涂层钛合金（对照）在强酸性氟化腐蚀介质（pH 2.0）中持续长达 240 天。使用动电位极化曲线、电化学阻抗谱和电感耦合等离子体原子发射谱（元素释放）定期测试样品。使用拉曼光谱、X 射线光电子能谱、原子力显微镜和扫描电子显微镜确定样品的完整性。使用单样本 t 检验、配对 t 检验和单因素方差分析与 Tukey 事后检验进行统计分析，预设显着性水平为 5%。

结果

GN 的腐蚀和元素损失可以忽略不计。在腐蚀挑战 240 天后，对照的腐蚀速率和粗糙度增加了两倍和十二倍，而 GN 保持不变。在所有测试时间点，纳米涂层都表现出非常高的结构完整性和覆盖面积 (>98%)。

意义

石墨烯纳米涂层可长时间保护钛合金免受腐蚀和溶解，同时保持高度的结构完整性。这种涂层具有持久保护钛和其他金属合金免受腐蚀的潜力。