Electrostatically Self-Assembled Magnetic Nanoparticles for High-Temperature Resistant and Friction-Controlled Lubrication System

Magnetic-responsive surfactants are considered promising smart lubricating
materials due to their significant stimulation response to applied magnetic
fields. In this study, four magneto-responsive surfactants are successfully
fabricated and encapsulated on the surface of molybdenum disulfide
nanosheets (MoS2@C18H37N+(CH3)3[XCl3Br]−, X = Fe, Ce, Gd, and Ho) as
base-oil components using electrostatic self-assembly, thereby constructing a
multi-functional magnetic lubrication system (MoS2@STAX).
Magnetorheological measurements confirm the remarkable responsiveness of
MoS
2@STACe lubricants at high shear rates and applied magnetic fields,
which is further corroborated by the constant proximity of the magnet. The
formation of dense carbon and tribo-chemical films between the friction
interfaces at elevated temperatures is the primary factor contributing to the
significant reduction in frictional wear. Notably, the magnetic lubricant
demonstrates a pronounced response behavior when subjected to an applied
magnetic field in the ceramic tribopair, even at lower magnetic fields. This
work presents concepts for the development of high-temperature resistant
and tunable lubrication additives by designing the material structure and
controlling the magnetic stimulation.