利用電化學沉積法於鎂金屬表面批覆鈣磷層其抗腐蝕性與生物活性之研究

A Study on Corrosion Resistance and Bioactivity of Ca-P Coated Magnesium by Electrodeposition

黃曉玫(HSIAO-MEI HUANG)

指導教授 ： 許世光 ； 許學全

中臺科技大學/健康科學院/牙體技術暨材料系碩士班/碩士(2017年)

摘要

近年來，鎂及其合金已逐漸被採用作為可生物降解的植入材料，廣泛應用於骨植入物及對心血管支架的研發。然而鎂金屬在生理環境下具有快速腐蝕之缺點，為了改善此缺點，本研究的主要目的為利用表面改質技術來提高鎂在體液中的耐腐蝕性與生物活性。
本研究首先利用電化學沉積法(Electrodeposition)試圖獲得最適當的電流參數，以及沉積時間，於鎂金屬表面批覆鈣磷塗層(CaP coating)，使其減緩鎂金屬的腐蝕速率與增加生物活性，然後，將具鈣磷塗層之鎂金屬進行表面結構及耐腐蝕性評估。使用硝酸鈣 (Ca(NO3)2·4H2O)和磷酸二氫銨(NH4H2PO4)配置電沉積溶液，在65˚C， 60分鐘，電壓控制於0.5 V，進行電沉積反應。
表面結構評估結果顯示，經由XRD分析證實鈣磷塗層能夠成功披覆在鎂金屬表面，另外由SEM的觀察顯示鎂金屬表面的鈣磷形貌以及披覆狀況良好，並使用EDS研究塗層的組成，結果表明，塗層中含有元素例如Ca，O和P，但不含Mg。
在耐蝕性方面，由電化學腐蝕分析結果顯示由極化曲線進行觀察，可以觀察到披覆鈣磷塗層的試片具有較高的腐蝕電位及較低的電流密度，因此推斷經鈣磷披覆的試片可以提高Mg在PBS溶液中的耐蝕性。在生物相容性測定中，與MG63骨母細胞共培養後，發現生長於披覆鈣磷之鎂試片表面的細胞貼附較為平坦且偽足呈現伸展的形態。
由上述研究結果顯示，利用電化學沉積在鎂金屬表面成功地沉積了鈣磷塗層，此鈣磷披覆層能有效提升鎂金屬的耐腐蝕性並增進其生物活性。

關鍵字

生物可降解材料 ； 純鎂 ； 電化學沉積 ； 耐腐蝕性

並列摘要

Recently, magnesium and its alloys have been adopted for developing and manufacturing biodegradable implant materials, especially in the development of bone implant materials and cardiovascular stents. However, magnesium exhibits the property of quick corrosion under physiological environment. In order to improve such a drawback, this study applies surface modification technique to improve its property of corrosion resistance in the body fluids, and bioactivity.
In this study, electrochemical deposition was applied to coat calcium phosphate (CaP) on the magnesium with various current parameters and deposition times adjusted for obtaining the material with optimal properties of optimal corrosion resistance and biological activity. And then, its surface structure and corrosion resistance were evaluated. Electrolytic solution will be prepared to calcium nitrate and ammonium dihydrogen phosphate at 65 ˚C for 60 minute , voltage was controlled at 0.5 V to carry out an electrodeposition reaction.
Evaluation of the surface structure shows that calcium phosphate has been successfully coated on the magnesium surface through XRD analysis, and the morphology of CaP coating appears smoothly distributed after SEM inspection.
The results revealed that coating layers contained elements such as Ca, O and P but no Mg. From the potentiodynamic polarization curve analysis, the potential curve of Ca-P coated magnesium was significantly higher than that of uncoated Mg in PBS solution. The results verify that the corrosion resistance properties of the coated Mg depend mainly on the Ca-P layer.
In biocompatibility assay, the MG63 osteoblast cells significant extended the pseudopodia and flat onto Ca-P coated Mg compared to uncoated after culturing.
From above results show that calcium phosphate coating was successfully precipitated on magnesium by electrochemical deposition. Preliminary results revealed that the Ca-P coated Mg could enhance the corrosion resistance and bioactivity.

並列關鍵字

Biodegradable material ； Magnesium ； Electrodeposition ； Corrosion resistance

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