A. Subbotin et al., FRICTION IN STRONGLY CONFINED POLYMER MELTS - EFFECT OF POLYMER BRIDGES, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 56(1), 1997, pp. 623-630
We propose a molecular theory of friction in confined polymer melts be
tween atomically smooth surfaces, taking polymer bridges between the s
urfaces into account. Using the activation friction model, we consider
the bridge adsorption-desorption dynamics and calculate the macroscop
ic friction force (the tangential stress) in the system as a function
of the imposed velocity. We show that the bridges result in the regime
where the friction force decreases with the increase of the imposed v
elocity. The friction force passes through maximum and minimum values
in the crossover range between linear and nonlinear regimes. We also i
nvestigate the stability of sliding in the regime with decreasing fric
tion force.