Thin Film Lubrication of Polymer Brushes

This study reports on the interfacial friction and adhesion properties of surface-tethered polymer thin films. We have previously shown that polydimethylsiloxane (PDMS) films with a nanoscale thickness manifest extremely low friction coefficients (mu= 0.0039) for a dry lubricant. In order to determine the origin of these results, we develop thin polymer brush layers from PDMS and other polymers and explore the effects of interfacial shear, surface coverage and brush structure. Using a combination of lateral force microscopy, nanoindentation, and ellipsometry experiments, we determine the chemical and physical processes responsible for the friction properties of these thin films.