Fluorographene,a new alternative to graphene,it not only inherits the 2-dimensional(2D)layered structure and outstanding mechanical properties,but also possesses controllable C-F bonds.It is meaningful to reveal the e...Fluorographene,a new alternative to graphene,it not only inherits the 2-dimensional(2D)layered structure and outstanding mechanical properties,but also possesses controllable C-F bonds.It is meaningful to reveal the evolution processes of the tribological behaviors from graphene to fluorographene.In this work,fluorinated reduced graphene oxide nanosheets(F-rGO)with different degree of fluorination were prepared using direct gas-fluorination and they were added into gas to liquid-8(GTL-8)base oil as lubricant additive to improve the tribological performance.According to the results,the coefficient of friction(COF)reduced by 21%,notably,the wear rate reduced by 87%with the addition of highly fluorinated reduced graphene oxide(HF-rGO)compared with rGO.It was confirmed that more covalent C-F bonds which improved the chemical stability of HF-rGO resisted the detachment of fluorine so the HF-rGO nanosheets showed less damage,as demonstrated via X-ray photoelectron spectroscopy(XPS),Raman spectra,and transmission electron microscopy(TEM).Meanwhile,the ionic liquid(IL)adsorbed on HF-rGO successfully improved the dispersibility of F-rGO in GTL-8 base oil.The investigation of tribofilm by TEM and focused ion beam(FIB)illustrated that IL displayed a synergy to participate in the tribochemical reaction and increased the thickness of tribofilm during the friction process.展开更多
基金the National Natural Science Foundation of China(51775540)Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(QYZDY-SSW-JSC009)the Youth Innovation Promotion Association,CAS(2017338).
文摘Fluorographene,a new alternative to graphene,it not only inherits the 2-dimensional(2D)layered structure and outstanding mechanical properties,but also possesses controllable C-F bonds.It is meaningful to reveal the evolution processes of the tribological behaviors from graphene to fluorographene.In this work,fluorinated reduced graphene oxide nanosheets(F-rGO)with different degree of fluorination were prepared using direct gas-fluorination and they were added into gas to liquid-8(GTL-8)base oil as lubricant additive to improve the tribological performance.According to the results,the coefficient of friction(COF)reduced by 21%,notably,the wear rate reduced by 87%with the addition of highly fluorinated reduced graphene oxide(HF-rGO)compared with rGO.It was confirmed that more covalent C-F bonds which improved the chemical stability of HF-rGO resisted the detachment of fluorine so the HF-rGO nanosheets showed less damage,as demonstrated via X-ray photoelectron spectroscopy(XPS),Raman spectra,and transmission electron microscopy(TEM).Meanwhile,the ionic liquid(IL)adsorbed on HF-rGO successfully improved the dispersibility of F-rGO in GTL-8 base oil.The investigation of tribofilm by TEM and focused ion beam(FIB)illustrated that IL displayed a synergy to participate in the tribochemical reaction and increased the thickness of tribofilm during the friction process.
