Ionic liquids as additive for lubricants

This thesis explores the use of ionic liquids (ILs) as lubricant additives, focusing on their potential for commercial applications and environmental benefits compared to conventional additives.Chapter 1 introduces the critical role of lubrication in reducing friction and wear in machinery, thus lowering energy costs and emissions. The chapter also covers the fundamentals of lubricants and the use of ILs as emerging additives in tribology, setting the stage for further exploration.

In Chapter 2, the miscibility and tribological performance of four commercially available tetraalkylphosphonium ILs in Group III+ base oils are evaluated. The findings from this chapter provide a foundation for subsequent chapters, offering insights into molecular designs and a more focused approach for evaluating new additive compounds.Chapter 3 investigates neutral boron compounds as additives. Boron’s ability to form hard metal boride films enhances wear resistance, and compounds containing nitrogen show improved friction reduction.