Mono-dispersed Ag nanoparticles decorated graphitic carbon nitride: An excellent lubricating additive as PPESK composite film
Beibei Chen, Mengjie Zhang, Kan Zhang, Zhe Dong, Jiaye Li, Gai Zhao
Abstract
Abstract Studies show that two dimensional (2D) nanomaterial and its hybrid have a great promise in tribology for the special laminar microstructure. However, the majority of performed investigations about 2D graphitic carbon nitride (g-C 3 N 4 ) nanosheets are most focused on energy storage, catalysis, adsorption, rarely tribology. In the present study, g-C 3 N 4 supporting mono-dispersed Ag nanoparticle hybrid (g-C 3 N 4 /Ag) is prepared, and its microstructure and chemical composition are determined. More specifically, the tribological performance as the lubricating additive of poly phthalazinone ether sulfone ketone (PPESK) composite is investigated using the ball-on-disc friction tester. Moreover, the corresponding enhancement mechanism is well proposed based on the experimental analysis and theoretical simulation. Obtained results show that Ag nanoparticles with a size of about 10–20 nm are homogeneously anchored on g-C 3 N 4 nanosheets, favoring for good compatibility between g-C 3 N 4 /Ag and PPESK. It is found that when 0.3 wt% of g-C 3 N 4 /Ag is added to PPESK, the friction coefficient and wear rate of PPESK decrease by 68.9% and 97.1%, respectively. These reductions are mainly attributed to the synergistic self-lubricating effect of Ag nanoparticles and g-C 3 N 4 nanosheet, the formation of transfer film, as well as the limited effect of g-C 3 N 4 /Ag on the shear deformation of PPESK composite film. Furthermore, it is found that the proposed g-C 3 N 4 /Ag-PPESK composite still keeps reasonable friction-reducing and wear-resistant properties under heavy loads and high rotating speeds. The present study demonstrates that the proposed g-C 3 N 4 /Ag hybrid is an excellent lubricating additive for polymer composites.