纯镁表面聚多巴胺膜的制备及表征

Preparation and Characterization of Polydopamine Films on Pure Magnesium Surface

为降低纯镁的腐蚀速率和赋予镁材料较好的细胞亲和力,通过溶液浸泡法在纯镁表面成功制备了单一聚多巴胺(PDA)膜和Mg(OH)2-PDA复合膜,通过单因素实验确定两种膜层制备的最佳工艺,利用场发射扫描电镜和动电位极化法分析了DA质量浓度与成膜时间对膜层形貌和耐蚀性的影响,利用傅立叶反射红外分析研究了两种膜层的化学结构.结果表明:制备PDA膜的最佳工艺条件为DA质量浓度1. 0 g/L、成膜时间12 h,制备Mg(OH)2-PDA复合膜的最佳工艺条件为DA质量浓度1. 5 g/L、成膜时间20 h;最佳工艺参数下基体的耐蚀性能得到显著提高,Mg(OH)2-PDA复合膜的耐蚀性最好;在纯镁上获得的PDA薄膜有明显裂纹缺陷;水热处理得到的Mg(OH)2膜层的微观结构为与聚多巴胺结合提供了更好位点,得到了更均匀的聚多巴胺膜.

In order to decrease the corrosion rate of the pure magnesium and improve cell affinity of magnesium materials,polydopamine(PDA)films and Mg(OH)2-PDA composite films are deposited on the pure magnesium surface.The optimum process of two kinds of films is investigated by the single factor experiment.The effects of DA mass concentration and film-forming time on film morphology and corrosion resistance are analyzed by field emission scanning electron microscope and dynamic potential polarization method.The chemical structure of the two films is studied by Fourier transform infrared spectroscopy.The results show that the optimum technological conditions for the preparation of PDA films is DA mass concentration of 1.0 g/L,and the film-forming of 12 h;the optimum technological conditions for the preparation of Mg(OH)2-PDA composite films are the DA mass concentration of 1.5 g/L and the film-forming time of 20 h.The corrosion resistance of the substrate is significantly improved under the optimum process parameters,and the corrosion resistance of Mg(OH)2-PDA composite films is the best.The obtained PDA films on pure magnesium have obvious crack defects.The microstructure of Mg(OH)2 films obtained by water heat treatment can provide a better site for the binding of polydopamines,which results in a more uniform polydopamine film.