Aromatic and polyaromatic compounds:

1
Friction of Self-Assembled, Polyaromatic
Monolayers M. Ruths, Department of Chemistry,
University of Massachusetts Lowell, MA 01854

• Aromatic and polyaromatic compounds
• Natural lubricants in mineral oils and fuel.
• Dependence of friction on the strength of
  adhesion?
• Adhesive contacts gt non-linear F vs. L, can be
  
• investigated by taking the size of the contact
  area
• (related to radius R of AFM probe) into
  account
• Used contact mechanics models for a compliant
• elastic film and a spherical probe (blue
  curves).
• Good agreement between different probe sizes.
• High packing density in adsorbed monolayer (SAM)
• gt lower critical shear stress Sc ( lower
  friction)
• At high loads, transitions occur in the
  self-assembled
• monolayers, causing a different friction
  response.