贵金属涂层超亲水-超疏水转化研究

Transformation Between Superhydrophilicity and Superhydrophobicity of Precious Metal Coating

为了探究贵金属涂层在空气中润湿性能,采用化学镀法在黄铜网表面成功制备了Au、Ag、Pt和Pd涂层,研究了涂层在空气中由超亲水向超疏水转化的变化速率。通过X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、能谱仪(EDS)、接触角测量仪对涂层的组成、形貌和润湿性进行表征,探讨了不同涂层表面形貌结构及化学组成对润湿性变化的影响。结果表明:放置9 d后Pd涂层表面有机碳含量最低,而Pd涂层水接触角增加最慢。同时Pt涂层虽然在初期水接触角增加较快,但因为其不具有微纳米双微观结构,最终的水接触角最小。因此涂层润湿性变化快慢与表面吸附空气中有机碳含量有关,而最终水接触角大小取决于涂层的表面微观结构。

To investigate the wettability of different precious metal coatings in air,Au,Ag,Pt,and Pd coatings were successfully prepared on brass screen surface via electroless plating method. The wettability transition ratio between superhydrophilicity and superhydrophobicity in air was studied. The coatings’ chemical composition, morphology, and surface wettability were characterized by X-ray diffraction,scanning electron microscopy,energy dispersive spectroscopy,and optical contact angle meter. The effects of surface morphology and chemical composition on the wettability transition of different coatings were investigated. The results showed that C content of the Pd coating after 9 d exposure in air is the least,and the increase of water contact angle is the slowest. Meanwhile,the contact angle of Pt coating increases rapidly in the initial stage,however its final contact angle is the least due to the lack of micro-nano binary structures.Therefore,the wettability transition ratio of the coating is related to the content of organic carbon absorbed by the surface,and the final water contact angle depends on the surface microstructure of the coating.