Piechowiak Daria, Miklaszewski Andrzej, Jurczyk Mieczysław
Institute of Materials Science and Engineering, Poznan University of Technology, Pl. M. Sklodowskiej-Curie 5, 60-965 Poznan, Poland.
Materials (Basel). 2020 Dec 17;13(24):5763. doi: 10.3390/ma13245763.
Hydroxyapatite (HAp) is the most widely used material for bio coating. The functional layer can be produced by many methods, however, the most perspective by its utility, easy to scale up, and simplicity aspects remains a hydrothermal treatment approach. In this work, an HAp coating was produced by low-temperature hydrothermal treatment on the ultrafine-grain beta Ti-xMo (x = 23, 27, 35 wt.%) alloys. The proposed surface treatment procedure combines acid etching, alkaline treatment (AT), and finally hydrothermal treatment (HT). The uniqueness of the approach relies on the recognition of the influence of the molar concentration of NaOH (5 M, 7 M, 10 M, 12 M) during the alkaline treatment on the growth of hydroxyapatite crystals. Obtained and modified specimens were examined structurally and microstructurally at every stage of the process. The results show that the layer after AT consist of titanium oxide and phases based on sodium with various phase relations dependent on NaOH concentration and base composition. The AT in 7 M and 10 M enables to obtain the HAp layer, which can be characterized as the most developed in terms of thickness and porosity. Finally, selected coated samples were investigated in terms of surface wettability test managed in time relation, which for the results confirm high hydrophilicity of the surfaces. Conducted research shows that the low-temperature hydrothermal processing could be considered for a possible adaptation in the drug encapsulation and delivery systems.
羟基磷灰石（HAp）是生物涂层应用最为广泛的材料。功能层可通过多种方法制备，然而，从实用性、易于扩大规模和操作简便性等方面来看，最具前景的方法仍是水热处理法。在本研究中，通过低温水热处理在超细晶粒β-Ti-xMo（x = 23、27、35 wt.%）合金上制备了HAp涂层。所提出的表面处理工艺结合了酸蚀、碱处理（AT）以及最后的水热处理（HT）。该方法的独特之处在于认识到碱处理过程中NaOH摩尔浓度（5 M、7 M、10 M、12 M）对羟基磷灰石晶体生长的影响。在工艺的每个阶段都对所得及改性后的试样进行了结构和微观结构检查。结果表明，碱处理后的涂层由氧化钛和基于钠的相组成，其相关系因NaOH浓度和碱组成而异。7 M和10 M的碱处理能够获得HAp层，就厚度和孔隙率而言，该层最为发达。最后，对选定的涂层样品进行了与时间相关的表面润湿性测试研究，测试结果证实了表面具有高亲水性。所开展的研究表明，低温水热处理可考虑用于药物封装和递送系统的可能适配。
