In-situ growth of layered double hydroxide films on biomedical magnesium alloy by transforming metal oxyhydroxide

摘要

Layered double hydroxide (LDH) films have been widely used for corrosion protection and medical applications. The most common synthesis methods for in-situ growth of LDH films on magnesium (Mg) alloys are hydrothermal treatment and steam coating. However, both the methods are mainly used for preparing Mg-Al LDH films and have limitations to in-situ fabricate other Mg-based LDH films which are suitable for biomedical application. Herein, a novel synthesis strategy for in-situ growth of LDH films on Mg alloys is proposed. Firstly, amorphous ferric oxyhydroxide (FeOOH) film was developed on Mg-Nd-Zn-Zr (JDBM) alloy by electrodeposition technique. Then, the as-prepared FeOOH films were transformed into Mg-Fe LDH film via hydrothermal treatment in water. In the LDH formation process, Mg2+ would enter into amorphous FeOOH and replace the Fe3+ quickly to form LDH. The thickness of the LDH films can be easily controlled by adjusting electrodeposition time. Electrochemical tests and cells culture experiments indicated that the as-prepared Mg-Fe LDH films improved corrosion resistance and biocompatibility of JDBM alloy. In addition, Mg-Mn LDH can also be prepared from amorphous manganese oxyhydroxide (MnOOH) via this newly developed two-step method. The present work provides a new strategy for preparation of LDH films on Mg alloys surface.