Arrieta Payares Lily Margareth, Gutierrez Pua Lizeth Del Carmen, Rincon Montenegro Juan Carlos, Fonseca Reyes Ana, Paredes Mendez Virginia Nathaly
Mechanical Engineering Department, Universidad del Norte, Km5 Vía Puerto Colombia, Barranquilla, 080005, Colombia.
Biomedical Engineering Department, Universidad Simón Bolívar, Barranquilla, Colombia, 080002.
Heliyon. 2024 Jul 20;10(15):e34772. doi: 10.1016/j.heliyon.2024.e34772. eCollection 2024 Aug 15.
Magnesium alloys have been extensively studied as degradable biomaterials for clinical applications due to their biocompatibility and mechanical properties. However, their poor corrosion resistance can lead to issues such as osteolysis and the release of gaseous hydrogen. This study investigated the influence of the activation time of magnesium surfaces in a sodium hydroxide (NaOH) solution on the concentration of active hydroxyl groups and corrosion resistance. The results indicated that immersion time significantly influences the formation of a corrosion-resistant film and the distribution of surface hydroxyl groups. Specifically, specimens treated for 7.5 h exhibited the highest concentration of hydroxyl groups and the most uniform oxide film distribution. Electrochemical tests demonstrated capacitive behavior and passive surface formation for all evaluated times, with the 7.5-h immersion in NaOH yielding superior corrosion resistance, lower current density, and a more efficient and thicker protective film. SEM and EDS analyses confirmed increased formation of Mg(OH)₂ for samples treated for 5 and 7.5 h, while a 10-h treatment resulted in a brittle, porous layer prone to degradation. Statistical analysis using ANOVA and Fisher's LSD test corroborated these findings. The optimal 7.5-h alkali treatment enhanced magnesium's corrosion resistance and surface properties, making it a promising candidate for orthopedic implants. However, further studies are necessary to assess biocompatibility and physiological responses before clinical implementation.
镁合金因其生物相容性和机械性能，作为临床应用的可降解生物材料已得到广泛研究。然而，其耐腐蚀性差会导致诸如骨溶解和气态氢释放等问题。本研究调查了镁表面在氢氧化钠（NaOH）溶液中的活化时间对活性羟基浓度和耐腐蚀性的影响。结果表明，浸泡时间显著影响耐腐蚀膜的形成和表面羟基的分布。具体而言，处理7.5小时的试样表现出最高的羟基浓度和最均匀的氧化膜分布。电化学测试表明，在所有评估时间内均呈现电容行为和钝化表面形成，在NaOH中浸泡7.5小时具有更好的耐腐蚀性、更低的电流密度以及更有效且更厚的保护膜。扫描电子显微镜（SEM）和能谱分析（EDS）证实，处理5小时和7.5小时的样品中氢氧化镁（Mg(OH)₂）的生成增加，而处理10小时则导致形成易于降解的脆性多孔层。使用方差分析（ANOVA）和费舍尔最小显著差异检验（Fisher's LSD test）的统计分析证实了这些发现。最佳的7.5小时碱处理提高了镁的耐腐蚀性和表面性能，使其成为骨科植入物的有前景候选材料。然而，在临床应用之前，有必要进一步研究以评估生物相容性和生理反应。
