Bilayer microstructure of antibacterial TiO2 coating on Ti6Al4V fabricated via micro-arc oxidation in W-containing electrolytes
Bilayer microstructure of antibacterial TiO2 coating on Ti6Al4V fabricated via micro-arc oxidation in W-containing electrolytes
复制标题
DOI：
10.1016/j.surfcoat.2021.127094
复制
发表时间：
2021-05
影响因子：
5.4
通讯作者：
Ruoyun Wang;Tong Zhou;Jie Liu;Xinwen Zhang;Fei Long;Lei Liu
中科院分区：
文献类型：
--
作者：
Ruoyun Wang;Tong Zhou;Jie Liu;Xinwen Zhang;Fei Long;Lei Liu
在我们之前的研究中，我们采用微弧氧化技术在Ti6Al4V表面制备了含W的TiO2涂层，并显示出优异的抗菌性能。然而，钨掺杂TiO2涂层的抗菌机理尚未阐明。为此，通过对微弧氧化涂层理化性能的分析，深入揭示了含钨TiO2涂层的抗菌机理。分析了含W和不含W的TiO2涂层的显微结构。表征结果表明，微弧氧化膜层为外层为非晶层，内层为多晶层的双层结构，含W的新型电解液体系有利于非晶层的形成，具有较强的电子存储能力。W掺杂TiO2涂层的优异抗菌性能与其强的电子存储能力有关，这种电子存储能力可以通过捕获细菌细胞挤压和微电偶腐蚀产生的电子，诱导足够的价带空穴（h+）在非晶外层积累，引起细菌细胞的氧化损伤。这一发现为抗菌涂料的设计提供了一种新的可控策略。
In our previous report, W-incorporated TiO2coating was fabricated on Ti6Al4V by micro-arc oxidization (MAO), and exhibited excellent antibacterial performance. However, the antibacterial mechanism of W-incorporated TiO2coating has not yet been clarified. Toward this end, the antibacterial mechanism of W-containing TiO2coating was thoroughly disclosed through analyzing the physicochemical properties of MAO coatings in this work. The microstructure of W-incorporated TiO2coating was analyzed in comparison with W-free TiO2coating. The characterization confirms that the MAO coating is a bilayer microstructure with an amorphous outer layer and poly-crystalline inner layer, and the W-containing new electrolyte system is beneficial to the formation of the amorphous layer with great electron storage capability. The excellent antibacterial activity of W-incorporated TiO2coating is related to its strong electron storage capability, which can induce sufficient valence-band holes (h+) to accumulate in the amorphous outer layer by trapping electrons from bacterial cell extrusion and micro-galvanic corrosion, arousing oxidation damage to bacterial cells. This finding provides a novel and controlled strategy to design antibacterial coatings.