A Mg-AI layered double hydroxide(Mg-AI-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 fre...A Mg-AI layered double hydroxide(Mg-AI-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-AI-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-AI-LDH coating.What's more,the MTT assay and livel dead staining showed that the LDH/PLL A-10 coating had good biocompatibility for Mouse NIH3T3 fibroblasts.The formation mechanism and the anti-corrosion mechanism of hybrid coatings were proposed.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.51601108 and 51571134)the SDUST Research Fund(Grant No.2014TDJH104)the Natural Science Foundation of Shandong Province(ZR2019MB053).
文摘A Mg-AI layered double hydroxide(Mg-AI-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-AI-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-AI-LDH coating.What's more,the MTT assay and livel dead staining showed that the LDH/PLL A-10 coating had good biocompatibility for Mouse NIH3T3 fibroblasts.The formation mechanism and the anti-corrosion mechanism of hybrid coatings were proposed.
