Atomistic simulations of the frictional properties of 2D materials: a review

Abstract

The two-dimensional (2D) materials are regarded as the ideal solid lubricants at micro- and nano-scale. Besides the experiments and analytical models, the atomistic simulations are important tools to investigate the frictional properties of 2D materials. This review will focus the recent atomistic simulation studies on frictional properties 2D materials with a particular emphasis on the density functional theory (DFT) calculations and molecular dynamics (MD) simulations. Starting from the proper calculation of long range dispersion forces, the correlations between the physical characteristics (e.g. electronic charge redistribution, interfacial commensurability, chemical modification, moiré superlattice, layer effect, atomic contact quality, defect, external fields, humidity and temperature) and frictional properties of 2D materials are reviewed for both the interlayer and surface sliding. Meanwhile, recent MD simulations about the phononic energy dissipation in friction of 2D materials are summarized. At last, some shortcomings in current simulation techniques are summarized and it is suggested that the atomistic simulations combined with machine learning will be a more powerful strategy to investigate the frictional properties of 2D materials.