Preparation of sandwich-like self-assembled n-octanethiol film containing doped silver nanoparticles on silicon wafer and evaluation of its tribological properties

•A sandwich-like trilayer self-assembled film was prepared by a three-step route.•The as-prepared trilayer film possesses excellent tribological properties.•The innermost layer is anchored on silicon substrate and also serves as a “bed”.•The intermediate layer is capable of enhancing the load-carrying capacity.•The outermost layer is soft and fluid-like to reduce the shearing stress.

A sandwich-like trilayer self-assembled film was prepared on silicon wafer. The micro- and macro-tribological properties of the self-assembled films were investigated. Findings indicate that as-prepared trilayer film possesses excellent friction-reducing and antiwear properties, which is attributed to its peculiar sandwich-like structure. In other words, the innermost layer is anchored on Si substrate and serves as an initial “bed” for nanoparticles to be inhabited, the intermediate layer of Ag nanoparticles is capable of enhancing the load-carrying capacity, and the outermost layer of self-assembled octanethiol film is soft and fluid-like which can reduce the shearing stress, also allows Ag nanoparticles to maintain strength and robustness. In one word, the load-carrying capacity and “rolling effect” of Ag nanoparticles and the sandwich-like structure of trilayer film account for its greatly improved friction-reducing and antiwear abilities and add to its feasibility as a candidate lubricant for protection of micro/nano-electro mechanical systems.

Graphical abstractA sandwich-like trilayer self-assembled film of n-octanethiol (denoted as C8) was prepared on single-crystal silicon wafer. The as-prepared MPTS-Ag-C8 trilayer film possesses excellent friction-reducing and antiwear properties, which is attributed to its peculiar sandwich-like structure.Figure optionsDownload full-size imageDownload as PowerPoint slide