Biocorrosion resistance and biocompatibility of Mg-Al layered double hydroxide/poly(L-lactic acid)hybrid coating on magnesium alloy AZ31

• 作者: Xiang SUN Qing-Song YAO Yu-Chao LI Fen ZHANG Rong-Chang ZENG Yu-Hong ZOU Shuo-Qi LI
• 来源期刊: 材料学前沿
• 年，卷（期）: 2020,（4）
• 所属期刊栏目: Research Articles
• 页码范围: 426-441
• 页数: 16页
• 语种: 英文

摘要

A Mg-AI layered double hydroxide(Mg-Al-LDH)coating was firstly synthesized via an in-situ steam coating growth method on the AZ31 Mg alloy,and then was modified with poly(L-lactic acid)(PLLA)via dipping and vacuum freeze-drying.The microstructure and composition of LDH/PLLA hybrid coating were analyzed by XRD,SEM,EDS and FT-IR.The biocorrosion behavior of hybrid coating was evaluated by potentiodynamic polarization,electrochemical impedance spectroscopy(EIS)and hydrogen evolution test in the Hank's solution.The results showed that LDH/PLLA coatings exhibited a much dense layer compared to the unmodified Mg-Al-LDH coating with unobvious boundary between PLLA and LDH coatings.The corrosion current density of the LDH/PLLA-10 hybrid coating decreased three orders of magnitude in comparison to its substrate.It was proven that the existence of the PLLA coating further prolonged the service life of the Mg-Al-LDH coating.What's more,the MTTassay and live/dead staining showed that the LDH/PLLA-10 coating had good biocompatibility for Mouse NIH3T3 fibroblasts.The formation mechanism and the anti-corrosion mechanism of hybrid coatings were proposed.