Preparation and Characterization of Polydopamine-Modified Ni/Carbon Nanotubes Friction Composite Coating

In this paper, dopamine (DA) was used for the surface modification of carbon nanotubes (CNTs) to solve the agglomeration problem. High resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS) were utilized to understand the morphology and presence of different elements in the modified CNTs. The treated CNT surfaces were wrapped by a pDA layer and the layer thickness was controlled by reaction time. The dispersion test showed that the treated CNTs remained uniformly dispersed in solution for more than 30 days. The Ni/CNTs@pDA composite coating on the mild steel specimen was obtained by the electrodeposition technique. Ball-on-disc friction-wear equipment and an electrochemical workstation were used to test the friction-wear and corrosion resistance of the composite coating. The results indicated that the Ni/CNTs@pDA coating showed excellent tribological performance and were superior to the pure Ni coating.