Delft University of Technology, Department of Biomechanical Engineering, Group of Biomaterials Technology, Mekelweg 2, 2628 CD Delft, The Netherlands.
Acta Biomater. 2011 Jun;7(6):2751-7. doi: 10.1016/j.actbio.2011.02.037. Epub 2011 Mar 22.
This research was aimed at investigating the growth mechanism of TiO(2)-Ag antibacterial coatings during plasma electrolytic oxidation (PEO) of Ti6Al7Nb biomedical alloy in an electrolyte based on calcium acetate/calcium glycerophosphate bearing Ag nanoparticles. The focus was on the mechanism of incorporation of Ag nanoparticles, their distribution and chemical composition within the porous coatings using high resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM) imaging techniques combined with energy dispersive X-ray spectroscopy (EDX) for chemical analyses. The PEO coatings were grown using different oxidation times, 10, 30, 60, 90, 120, 180, 240 and 300 s. The electron microscopy results confirmed the formation of a porous coating with incorporated Ag nanoparticles from the initial stages of oxidation (i.e. 10 s), with further Ag incorporation as the PEO process was continued for longer durations. The Ag nanoparticles were embedded in the dense oxide layer, fused into the pore walls and on the surface of the coatings without any change in their morphology or chemistry as detected by HRTEM, SEM and EDX. Ag seems to be delivered to the sites of coating growth (where dielectric breakdown occurs) through different transport pathways, i.e. open pores, cracks and short-circuit channels.
本研究旨在探讨在基于含有 Ag 纳米粒子的醋酸钙/甘油磷酸钙的电解液中，通过等离子体电解氧化（PEO）Ti6Al7Nb 医用合金，TiO(2)-Ag 抗菌涂层的生长机制。研究重点是利用高分辨率透射电子显微镜（HRTEM）和扫描电子显微镜（SEM）成像技术以及能量色散 X 射线能谱（EDX）化学分析，研究 Ag 纳米粒子的掺入机制、其在多孔涂层中的分布和化学组成。使用不同的氧化时间（10、30、60、90、120、180、240 和 300 s）生长 PEO 涂层。电子显微镜结果证实，从氧化的初始阶段（即 10 s）开始就形成了带有掺入 Ag 纳米粒子的多孔涂层，随着 PEO 过程的继续进行，Ag 的进一步掺入。Ag 纳米粒子嵌入在致密的氧化物层中，熔合在孔壁和涂层的表面，其形态或化学性质没有任何变化，这是通过 HRTEM、SEM 和 EDX 检测到的。Ag 似乎通过不同的传输途径（即开放孔、裂缝和短路通道）输送到涂层生长的部位（介电击穿发生的部位）。
