| Abstract: | 通過脈衝式電化學沉積法合成鈷取代氫氧基磷灰石沉積於二氧化鈦奈米管上，探討粉體的磁性與生物降解性。首先將非晶型的二氧化鈦奈米管透過退火處理轉變其晶相，退火升溫速率為每分鐘10 °C，分別升溫至400、600、800 °C後恆溫一小時，試片分別命名為T34-400A、T34-600A以及T34-800A。結果發現，T34-400A轉變成銳鈦礦，試片T34-600A轉變成金紅石相，T34-800A的金紅石含量比T34-600A多。將以上試片作為陰極進行鈷取代氫氧基磷灰石合成，隨著退火溫度上升，粉體尺寸由110縮小為86 nm，粉體中氧化鈷的結晶尺寸隨著退火溫度上升，結晶尺寸依序降低為2.232 nm、1.693 nm、1.510 nm，因此鈷取代氫氧基磷灰石的飽和磁化強度，會隨著氧化鈷結晶尺寸降低而降低。由生物降解性評估，短時間內溶液pH值由高到低依序為T34-600A、T34、T34-400A，浸泡一個月後則無差異。另一方面，本研究在電解液中加入過氧化氫(600 ppm、1200 ppm、2000 ppm)，以未退火處理之二氧化鈦奈米管基材作為陰極，結果發現當過氧化氫濃度增加，顆粒尺寸會從110提高至133 nm，而氧化鈷結晶尺寸從2.232 nm，分別降低為1.801 nm、0.883 nm、0.575 nm，因此過氧化氫飽和磁化強度也隨著氧化鈷結晶尺寸降低而降低。生物降解性評估發現，PBS中的pH值會隨過氧化氫濃度增加而上升，且鈷離子釋放程度與過氧化氫濃度成正比。綜合兩組的粉體性質，T34-CoHA中有較高的飽和磁化強度，因此適合用於MRI，而2000 ppm-CoHA有較優異的生物降解性，因此適合用於骨填充材料。
Cobalt-substituted hydroxyapatite (Co-HA) was prepared on a titanium dioxide nanotubes (TNT) by pulsed electrochemical deposition. First, phase transitions of TNT is prepared in Argon for 1 hr at different temperatures (400, 600, 800 °C). The samples were named T34-400A, T34-600A, and T34-800A. Crystal structure of TNT was investigated by XRD. T34-400A is transformed into anatase phase and T34-600A is transformed into rutile phase. Then T34-800A is show more rutile phase than T34-600A. The above samples were used on Co-HA synthesis as a cathode. The result was found that particle size of Co-HA was decreased from 110 nm to 86 nm with annealing temperature increased. Crystal size of cobalt oxide increases with annealing temperature, and crystal size decreases from 2.232 to 1.693, and 1.510 nm. Therefore, the saturation magnetization of Co-HA decreases with the decrease of crystal size of cobalt oxide. The biodegradability of Co-HA was evaluated by immersed in PBS. In a short time, the pH value of PBS from high to low is T34-600A, T34 and T34-400A. However, no difference between pH value of PBS after 1 month immersion. In the second part, effect of H2O2 concentration (600, 1200, 2000 ppm) in electrolyte on Co-HA synthesized on un-annealing TNT was evaluated. The results show that when the concentration of H2O2 increases, the particle size increased from 110 to 133 nm and the crystal size of cobalt oxide decrease from 2.232 to 1.801, 0.883, and 0.575 nm, respectively. Therefore, the saturation magnetization of hydrogen peroxide also decreases as the crystal size of cobalt oxide decreases. Biodegradability test found that the pH in PBS increased with increasing H2O2 concentration, and the release of cobalt ions was proportional to the concentration of hydrogen peroxide. Combining the powder properties of the two groups, T34-CoHA has a higher saturation magnetization and is suitable for MRI. However, 2000 ppm-CoHA has excellent biodegradability and is suitable for bone filling materials. |
