Fabrication and Tribological Investigation of a Novel Hydrophobic Polydopamine/Graphene Oxide Multilayer Film

Polydopamine (PDA)/graphene oxide (GO) multilayer was successfully constructed on the surface of silicon substrate by a layer-by-layer self assembling process. In order to further obtain hydrophobic outer surface, low energy molecules of 1H, 1H, 2H, 2H-perfluorodecyltrichlorosilane (PFDTS) were grafted thereon and the sample was coded as PDA/GO-PFDTS. The microstructures, chemical compositions, and morphologies of PDA/GO-PFDTS were characterized by the water contact angle (WCA) measurements, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). In particular, the tribological performances were investigated by AFM and ball-on-plate tribometer. Experimental results showed that PDA/GO-PFDTS could lower the stiction and friction greatly as compared with the bare substrate and control samples. It was indicated that the as-fabricated film of PDA/GO-PFDTS was a very promising candidate for solving the tribological problems in micro/nano devices.