From Static to Kinetic Friction in Confined Liquid Films
Günter Reiter 1,
A. Levent Demirel 1, and
Steve Granick 1
1 Materials Research Laboratory and Department of Materials Science and Engineering, University of Illinois, Urbana, IL 61801, USA.
The transition from rest to sliding contact of atomically smooth solids separated by molecularly thin liquid films was studied. The films could be deformed nearly reversibly to a large fraction of the film thickness. The modulus of elasticity and yield stress were low, considerably less than for a molecular crystal or glass in the bulk. The transition to dissipative sliding was typically (but not always) discontinuous. The dissipative stress was then nearly velocity-independent. The similar response of monolayers strongly attached to the solid surfaces, presenting a well-defined interface for sliding, suggests that the physical mechanism of sliding may involve wall slip.
Submitted on September 23, 1993
Accepted on January 31, 1994
