Tribology

Summary: In the field of tribology we have been heavily involved in the study of the frictional properties of quasicrystalline surfaces and over the past year the properties of quasicrystalline approximants. Friction between the approximant surface has been shown to be significantly higher than friction between the quasicrystal surfaces. This is the result of measurements between perfectly clean surfaces in ultra-high vacuum and surfaces exposed to conditions of controlled oxidation.

Project members: Esteban Broitman

Chiral Surfaces

Summary: In the study of enantiospecific properties of naturally chiral surfaces we have demonstrated for the first time a diastereomeric effects in the barrier to desorption of small chiral molecules from chiral surfaces. The desorption barrier controls desorption kinetics and an enantiospecific effect is needed to achieve chiral separations.

Project members: Layton Baker, Wai Yeng Cheong, Ye Huang , Vladimir Pushkarev

Data Storage Systems

Summary: Ongoing studies of the surface chemistry of lubricants on data storage media have focused on the effects of contaminants on the bonding of fluoroether lubricants to a-CHx films. It has been shown that water will reduce the interactions of fluoroether lubricants with these surfaces while it enhances the interaction of alcohol endgroups with these surfaces.

Project members: Esteban Broitman, Yang Dong

Vapor Phase Lubrication

Summary: Vapor phase lubrication is a promising technology for lubricating moving parts that must operate at high temperatures (greater than 550 °C). In this research we are studying the nature of the decomposition mechanism of vapor phase lubricants (tricresylphosphate and tributylphosphate) on Fe surfaces using temperature programmed reaction spectroscopy and Auger electron spectroscopy. This work has applications in many fields, but the vapor phase lubrication of jet engines is of particular interest to industry.

Project members: Donggun Kim