Creeping friction dynamics and molecular dissipation mechanisms in glassy polymers
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Updated: Aug 30, 2026

Cooling Rate Dependent Ellipsometry Measurements to Determine the Dynamics of Thin Glassy Films
Published on: January 26, 2016
1Department of Chemical Engineering, University of Washington, Seattle, WA 98195, USA.
Abstract:
The dissipation mechanism of nanoscale kinetic friction between an atomic force microscopy tip and a surface of amorphous glassy polystyrene has been studied as a function of two parameters: the scanning velocity and the temperature. Superposition of the friction results using the method of reduced variables revealed the dissipative behavior as an activated relaxation process with a potential barrier height of 7.0 kcal/mol, corresponding to the hindered rotation of phenyl groups around the C-C bond with the backbone. The velocity relationship with friction F(v) was found to satisfy simple fluctuation surface potential models with F proportional to const-ln(v) and F proportional to const-ln(v)2/3.
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