Universidade Federal do Paraná, Programa de Pós-Graduação em Engenharia e Ciência dos Materiais - PIPE, Curitiba, PR, Brazil.
Universidade Federal do Paraná, Programa de Pós-Graduação em Engenharia e Ciência dos Materiais - PIPE, Curitiba, PR, Brazil.
J Mech Behav Biomed Mater. 2018 Jan;77:347-352. doi: 10.1016/j.jmbbm.2017.08.010. Epub 2017 Aug 5.
Niobium plates were electrochemically treated by Plasma Electrolytic Oxidation (PEO) with electrolytes containing phosphorous and/or calcium. Three different electrolyte and experimental parameters were used forming three different surfaces. Film morphology, thickness, and chemical composition were analyzed by scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). A profilometer and the sessile drop technique measured the average surfaces roughness (Ra) and contact angles respectively. X-ray diffraction technique (XRD) analyzed the oxide crystallinity, and scratch tests evaluated the film adhesion. All oxidized surfaces presented pores, without observed cracks. Comparing the different experimental conditions, films obtained with phosphoric acid (P100) show superficial pores, phosphorus incorporation, high hydrophilicity, non-crystalline oxide formation, and good scratch resistance. Films treated with calcium acetate electrolyte (Ca100), compared to P100 exhibit smaller size pores and film thickness, smaller hydrophilicity, and lower scratch resistance. They also demonstrated higher oxide crystallinity, calcium incorporation, and pores interconnections. When the PEO was executed with a blended electrolyte containing calcium acetate and phosphoric acid (Ca50P50) the formed films presented the highest thickness, high phosphorus incorporation, and the lowest contact angle compared with other films. In addition, the pores size, the scratch resistance, calcium incorporation, and oxide crystallinity present intermediate values compared to P100 and Ca100 films. Film crystallinity seems to be influenced by calcium incorporation, whereas, hydrophilicity is phosphorus amount dependent. The pores amount and their interconnections reduced the scratch resistance. Surface features obtained in this work are largely mentioned as positive characteristics for osseointegration processes.
采用含有磷和/或钙的电解液通过等离子电解氧化（PEO）对铌板进行电化学处理。使用三种不同的电解液和实验参数形成三种不同的表面。通过扫描电子显微镜（SEM）和能量色散光谱（EDS）分析薄膜的形貌、厚度和化学成分。通过轮廓仪和固着液滴技术分别测量平均表面粗糙度（Ra）和接触角。X 射线衍射技术（XRD）分析了氧化物的结晶度，划痕试验评估了薄膜的附着力。所有氧化后的表面都有孔，没有观察到裂纹。比较不同的实验条件，用磷酸（P100）获得的薄膜表现出表面多孔、磷的掺入、高亲水性、非晶态氧化物形成和良好的耐划伤性。与 P100 相比，用醋酸钙电解液（Ca100）处理的薄膜表现出较小的孔径和薄膜厚度、较小的亲水性和较低的耐划伤性。它们还表现出更高的氧化物结晶度、钙的掺入和孔的连通性。当 PEO 采用含有醋酸钙和磷酸的混合电解液（Ca50P50）执行时，与其他薄膜相比，形成的薄膜具有最高的厚度、高磷掺入和最低的接触角。此外，与 P100 和 Ca100 薄膜相比，孔径、耐划伤性、钙掺入和氧化物结晶度的值都处于中间水平。薄膜的结晶度似乎受到钙掺入的影响，而亲水性则取决于磷的含量。孔的数量及其连通性降低了耐划伤性。这项工作中获得的表面特征在很大程度上被认为是有利于骨整合过程的特征。
