Nanoscale boundary lubrication studies

Abstract

Boundary films are formed by physisorption, chemisorption, and chemical reaction. A good boundary lubricant should have a high degree of interaction between its molecules and the solid surface. As a general rule, liquids are good lubricants when they are polar and thus able to grip solid surfaces (or be adsorbed). In this chapter, we present an overview of various perfluoropolyethers (PFPEperfluoropolyether (PFPE)s) and ionic liquid films. PFPEs exhibit the highest chemical and thermal stability. Ionic liquid films possess efficient heat transfer properties and some electrical conductivity properties of interest. We present a summary of nanodeformation, molecular conformation, and lubricant spreading studies, followed by an overview of the nanotribological properties of polar and nonpolar PFPEs and ionic liquid films studied by atomic force microscopy (AFMatomic force microscopy (AFM)), and chemical degradation studies using a high vacuum tribotest apparatus.