Deposition of Ag nanoparticles on polydopamine-functionalized CNTs for improving the tribological properties of PPESK composites

In this study, CNTs were first modified by polydopamine (PDA) to facilitate their surface activation and then Ag nanoparticles were in-situ grown on CNT-PDA to obtain CNT-PDA/Ag. The effects of functionalized CNTs on the tribological behaviors of poly (phthalazinone ether sulfone ketone) (PPESK) were investigated. Results revealed that PDA layer could not only increase the active functional groups on the CNT surface, but also act as an activated platform for the deposition of mono-dispersed Ag nanoparticles. The decoration of Ag nanoparticles decreased the interaction among CNTs, which was conducive to their good dispersion. Besides, by filling 0.3 wt% CNT-PDA/Ag, the thermal properties of PPESK were significantly improved, and its friction-reduction and antiwear performances were the best among all PPESK composites, due to the good interfacial interaction between CNTs and PPESK, the synergistic reinforcing and lubricating effect of CNTs and Ag nanoparticles, as well as the lubricating effect of transfer film.