水分子诱导类金刚石薄膜表面的变化

Surface Changes of Diamond-like Carbon Films Induced by Water Molecules

利用等离子体增强化学气相沉积技术在单晶硅表面制备了类金刚石(DLC)薄膜,并将其分别浸泡在经磁场处理和未经磁场处理的去离子水中。利用X射线光电子能谱仪、原位纳米力学测试系统和高速摩擦磨损测试仪分析和比较在水和磁化水中浸泡后DLC薄膜表面的变化情况。结果表明:磁场作用将改变经过DLC薄膜表面微孔或缺陷渗进薄膜内的水分子个数,进而诱导DLC薄膜表面发生变化。在含水环境中,比如液体水中,水分子参与反应并诱导C=C键朝向C-C或C-H键转化,并且氢原子将进入薄膜内中和膜内自由基,进而导致其硬度,摩擦因数升高。

Diamond-like carbon films were successfully deposited on Si substrate by plasma enhanced chemi cal vapor deposition, and immersed in deionized water with or without magnetic fields. Soaked surfaces of the films in deionized water with or without magnetic fields were investigated by X-ray photoelectron spectroscopy （XPS）, nanoindentation and tribometer. It is found that the magnetic fields increase the number of water mol- ecules penetrating into DLC films, resulting in the surface changes of the films. When water molecules exist, the conversion from C=C bonds to C-H bonds is induced, and H atoms enter into films, and neutralize free radicals, resulting the increase of hardness and friction coefficient.