Molecular basis of lubrication

Lubrication is an art that has been practiced for thousands of years from the early days of our human civilization. The study of lubrication as a science began in the 17th century with the development of bearings and axles. In the early 21st century, the advent of automobiles and steam engines spurred the development of modern complex lubricants consisting of base oils and chemical additives. The development, however, has been mostly empirical in nature. The detailed mechanisms of the chemistry and why they worked were not understood. Rapid advancements in analytical instrumentations and techniques in the last several decades offer an unprecedented opportunity to analyze the complex chemistry and probe the surfaces for chemical evidence. Recent developments in nanotechnology provide further ability to examine phenomena and mechanisms at the nanometer level. As a result of these advances, our understanding of the complex lubrication system has improved significantly. This paper will attempt to provide a molecular basis of how lubricant and additives function in lubrication. Monomolecular thin films have been developed to investigate the fundamental mechanism of boundary lubricating films. Results provide additional insights of how antiwear films work in the lubrication system. Prospect for applying this know-how may result in a revolutionary change in our current lubricating technology. Published by Elsevier Ltd.