Non-equilibrium phase behavior of confined molecular films at low shear rates
File(s)
Accepted version
Author(s)
Mackowiak, S
Heyes, D
Pieprzyk, S
Dini, D
Branka, AC
Type
Journal Article
Abstract
In a recent publication [Maćkowiak et al., J. Chem. Phys. 145, 164704 (2016)] the results of Non-Equilibrium Molecular Dynamics (NEMD) simulations of confined sheared Lennard-Jones molecular films have been presented. The present work builds on that study by focusing on the low wall speed (shear rate) regime. Maps are given of the steady-state structures and corresponding friction coefficients in the region where a transition from static to kinetic friction is observed. The boundary between static and kinetic friction regions is determined as a function of wall speed and applied pressure, which is located for wall speeds up to about 0.8 m s−1. It was found that stick-slip behavior extends to pressures as high as 1000 MPa. The NEMD equations of motion are shown to be consistent with the Prandtl–Tomlinson model in the ‘soft spring’ limit, which leads to a new expression for the friction coefficient. This study provides new details and insights into the nature of anomalous friction behavior in the so-called Plug-Slip part of the nonquilibrium phase diagram regime.
Date Issued
2017-09-15
Date Acceptance
2017-08-07
Citation
Physica Status Solidi B - Basic Solid State Physics, 2017, 254 (12)
ISSN
0370-1972
Publisher
Wiley
Journal / Book Title
Physica Status Solidi B - Basic Solid State Physics
Volume
254
Issue
12
Copyright Statement
2018-09-15
This is the peer reviewed version of the following article: Maćkowiak, S., Heyes, D. M., Pieprzyk, S., Dini, D. and Brańka, A. C. (2017), Non-Equilibrium Phase Behavior of Confined Molecular Films at Low Shear Rates. Phys. Status Solidi B, 254: n/a, 1600862, which has been published in final form at https://dx.doi.org/10.1002/pssb.201600862 This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Grant Number
EP/N025954/1
Subjects
Science & Technology
Physical Sciences
Physics, Condensed Matter
Physics
anomalous friction
confined systems
Lennard-Jones films
molecular dynamics
Prandtl-Tomlinson model
shear
FRICTION
NANOSCALE
0204 Condensed Matter Physics
0206 Quantum Physics
1007 Nanotechnology
Applied Physics
Publication Status
Published
Article Number
1600862