Achieving Greener, Super-Robust Performance Water-Based Lubrication: Obtained by a Multifunctional Ionic Liquid Aqueous System and Formation of Unique Interfacial Interactions

Owing to the green, high-performance, and application-specificworkconditions, water-based lubricating systems show unlimited potentialfor chemical engineering development. The interfacial behavior offunctional additives in aqueous systems is complex and variable dueto polarity and interfacial activity, thus showing important researchsignificance. Herein, five novel ionic liquids were synthesized; theirunique interfacial behavior in the polar water system contributesa lot to the advanced corrosion resistance and the improved extremepressure-bearing capacity. The polar groups in the molecular structureof ionic liquids can adsorb preferentially in competition with watermolecules, resulting in the formation of an adsorption layer witha high elastic modulus on the metal surface. Benefiting from the tribochemicalreaction and the strong polar adsorption effect, the tribofilm atthe sliding asperity exhibited effective antiscuffing and antiwearperformance. Moreover, their characteristic cationic groups enrichthe driving force of the molecular self-assembly process and enhancethe ability to form ordered molecular aggregates, whose behavior inan aqueous system facilitates super-robust lubricity. This work canpromote the in-depth understanding, future design, and optimizationof the aqueous lubricating system, providing content enrichment andexpansion for the lubrication technology for harsh service conditions. A green, sustainable, and high-performancemultifunctionalIL water-based lubricating system is constructed with the characteristicsof simple preparation, low cost, and environmental friendliness.