Chemical control of friction: mixed lubricant monolayers

Controlling frictional behavior in nanoscale sheared systems can be made possible when the relationship between the macroscopic frictional response and the microscopic properties of the sheared systems is established. Here, a new approach is proposed for tuning the frictional response and obtaining desirable frictional properties. This tuning is achieved through shear-induced phase transitions in a mixed lubricant monolayer consisting of a base solvent and an additive. The interaction between the solvent and additive molecules and their relative concentrations are shown to be the major parameters in determining the magnitude of the friction force and the nature of the response (stick-slip or sliding).