Preparation of Titania Gel Film with Graded Ca ion Distribution by Electrochemical Technique and Providing Titanium for Bone Substitution with High Bioactivity

采用H_2O_2水溶液氧化钛，在空气中简单加热，阳极极化生成氧化钛层。这些层在模拟体液中诱导仿生磷灰石沉积的能力通过x射线衍射仪和扫描电子显微镜进行了评估。在200 ~ 700℃的空气中加热产生的氧化层性能很差。同样，用质量为30%的H_2O_2溶液处理对仿生磷灰石沉积几乎无效，但随后在300 ~ 700℃的空气中加热可显著提高其沉积能力。这种增强是由于加热时锐钛矿析出导致磷灰石外延诱导成核。几mmol/l的Ta(V)的加入产生了中等的积极作用。氧化层由9.5 V vs. Ag/AgCl的阳极氧化和随后的阳极氧化形成。阴极极化沉积钙离子形成氢氧化钙。氢氧化钙在模拟体液中浸泡产生碳酸钙，为磷灰石成核提供了场所，并因磷灰石的形成而耗尽。

Titanium was oxidized with H_2O_2 aqueous solutions, simple heating in the air, and anode polarization to yield titanium oxide layers. Ability of those layers to induce biomimetic apatite deposition in a simulated body fluid was evaluated by X-ray diffractometry and scanning electron microscopy. Heating in air at temperatures in the range 200 to 700℃ yielded the oxide layers with little ability. The treatment with 30 mass% H_2O_2 solutions was similarly almost ineffective for biomimetic apatite deposition, but the subsequent heating at 300 to 700℃ in air significantly improved the ability. Such enhancement was attributed to an epitaxial induction of apatite nucleation caused by the precipitation of anatase on heating. Addition of Ta(V) in a few mmol/l caused a moderate positive effect. The oxide layers derived from anode oxidation at 9.5 V vs. Ag/AgCl followed by the anode oxidation. The cathode polarization deposited calcium ions as calcium hydroxide. Calcium carbonate was yielded from the hydroxide when soaked in the simulated body fluid, and provided the site of apatite nucleation as well as it was exhausted by the formation of apatite.