Equilibrium molecular dynamics evaluation of the solid-liquid friction coefficient: role of timescales
arXiv:2304.12471 · doi:10.1063/5.0155628
Abstract
Solid-liquid friction plays a key role in nanofluidic systems. Yet, despite decades of method development to quantify solid-liquid friction using molecular dynamics (MD) simulations, an accurate and widely applicable method is still missing. Here, we propose a method to quantify the solid-liquid friction coefficient (FC) from equilibrium MD simulations of a liquid confined between parallel solid walls. In this method, the FC is evaluated by fitting the Green-Kubo (GK) integral of the S-L shear force autocorrelation for the range of time scales where the GK integral slowly decays with time. The fitting function was derived based on the analytical solution considering the hydrodynamic equations in our previous work [H. Oga et al., Phys. Rev. Research 3, L032019 (2021)], assuming that the timescales related to the friction kernel and to the bulk viscous dissipation can be separated. By comparing the results with those of other equilibrium MD-based methods and those of non-equilibrium MD for a Lennard-Jones liquid between flat crystalline walls with different wettability, we show that the FC is extracted with excellent accuracy by the present method, even in wettability regimes where other methods become innacurate. We then show that the method is also applicable to grooved solid walls, for which the GK integral displays a complex behavior at short times. Overall, the present method extracts efficiently the FC for various systems, with easy implementation and low computational cost.
arXiv comment22 pages, 6 Figures
References in corpus (12)
- Nanofluidics, from bulk to interfaces
- Friction of Water on Graphene and Hexagonal Boron Nitride from ab initio Methods: Very Different Slippage Despite Very Similar Interface Structures
- Boundary conditions at a fluid - solid interface
- Influence of wetting properties on the hydrodynamic boundary condition at a fluid-solid interface
- On the Green-Kubo relationship of the liquid-solid friction coefficient
- Thermal conductance at the interface between crystals using equilibrium and non-equilibrium molecular dynamics
- Equilibrium Simulation of the Slip Coefficient in Nanoscale Pores
- Slip Length Measurement in Rectangular Graphene Nanochannels with a 3D Flow Analysis
- Molecular interpretation of the non-Newtonian viscoelastic behavior of liquid water at high frequencies
- Statistical mechanical expressions of slip length
- Equilibrium measurement method of slip length based on fluctuating hydrodynamics
- Microscopic determination of macroscopic boundary conditions in Newtonian liquids