Solvation forces in simple dense fluids. I

Snook, Ian K.; Megen, W. van

doi:10.1063/1.439489

Cited by 296 publications

(165 citation statements)

References 23 publications

Supporting

Mentioning

157

Contrasting

Order By: Relevance

“…Confined lubricants behave very differently to their bulk counterparts under shear, and density inhomogeneity can lead to the breakdown of continuum approximations such as Navier-Stokes hydrodynamics [133]. Density oscillations in confined fluids were first identified in Monte−Carlo (MC) simulations of L−J liquids [65,134]. Shortly afterwards, surface forces apparatus (SFA) experiments by Horn and Israelachvili on confined octamethylcyclotetrasiloxane (OMCTS) [135] (a quasi-spherical molecule) showed that the force between two surfaces does not evolve smoothly with the separation distance as predicted by the van der Waals theory.…”

Section: Confined Nemd Simulations Of Liquid Lubricantsmentioning

confidence: 99%

“…This technique was developed from GCEMC (grandcanonical ensemble Monte Carlo) [65] to investigate interesting results from surface force apparatus (SFA) experiments of confined liquid films [66]. In GCMD simulations, a reservoir of fluid molecules surrounds the confined system [64], thus allowing molecules to be "squeezed out" from between the solid surfaces in one or more directions at high pressure [67].…”

Section: Temperature and Pressure Controlmentioning

confidence: 99%

See 1 more Smart Citation

Advances in nonequilibrium molecular dynamics simulations of lubricants and additives

2018

View full text Add to dashboard Cite

Nonequilibrium molecular dynamics (NEMD) simulations have provided unique insights into the nanoscale behaviour of lubricants under shear. This review discusses the early history of NEMD and its progression from a tool to corroborate theories of the liquid state, to an instrument that can directly evaluate important fluid properties, towards a potential design tool in tribology. The key methodological advances which have allowed this evolution are also highlighted. This is followed by a summary of bulk and confined NEMD simulations of liquid lubricants and lubricant additives, as they have progressed from simple atomic fluids to ever more complex, realistic molecules. The future outlook of NEMD in tribology, including the inclusion of chemical reactivity for additives, and coupling to continuum methods for large systems, is also briefly discussed.

show abstract

Section: Confined Nemd Simulations Of Liquid Lubricantsmentioning

confidence: 99%

Section: Temperature and Pressure Controlmentioning

confidence: 99%

Advances in nonequilibrium molecular dynamics simulations of lubricants and additives

2018

View full text Add to dashboard Cite

show abstract

“…It is induced by the sharp cutoff in fluid density at the wall and the pair correlation function g(r) between fluid atoms (Abraham, 1978;Toxvaerd, 1981;Nordholm and Haymet, 1980;Snook and van Megen, 1980;Plischke and Henderson, 1986). An initial fluid layer forms at the preferred wall-fluid spacing.…”

Section: A Flow Boundary Conditionsmentioning

confidence: 99%

Computer Simulations of Friction, Lubrication, and Wear

Robbins¹,

Müser²

2000

Mechanics &Amp; Materials Science

View full text Add to dashboard Cite

Computer simulations have played an important role in understanding tribological processes. They allow controlled numerical "experiments" where the geometry, sliding conditions and interactions between atoms can be varied at will to explore their effect on friction, lubrication, and wear. Unlike laboratory experiments, computer simulations enable scientists to follow and analyze the full dynamics of all atoms. Moreover, theorists have no other general approach to analyze processes like friction and wear. There is no known principle like minimization of free energy that determines the steady state of non-equilibrium systems. Even if there was, simulations would be needed to address the complex systems of interest, just as in many equilibrium problems.Tremendous advances in computing hardware and methodology have dramatically increased the ability of theorists to simulate tribological processes. This has led to an explosion in the number of computational studies over the last decade, and allowed increasingly sophisticated modeling of sliding contacts. Although it is not yet possible to treat all the length scales and time scales that enter the friction coefficient of engineering materials, computer simulations have revealed a great deal of information about the microscopic origins of static and kinetic friction, the behavior of boundary lubricants, and the interplay between molecular geometry and tribological properties. These results provide valuable input to more traditional macroscopic calculations. Given the rapid pace of developments, simulations can be expected to play an expanding role in tribology.In the following chapter we present an overview of the major results from the growing simulation literature. The emphasis is on providing a coherent picture of the field, rather than a historical review. We also outline opportunities for improved simulations, and highlight unanswered questions.We begin by presenting a brief overview of simulation techniques and focus on special features of simulations for tribological processes. For example, it is well known that the results of tribological experiments can be strongly influenced by the mechanical properties of the entire system that produces sliding. In much the same way, the results from simulations depend on how relative motion of the surfaces is imposed, and how heat generated by sliding is removed. The different techniques that are used are described, so that their influence on results can be understood in later sections.The complexities of realistic three-dimensional systems can make it difficult to analyze the molecular mechanisms that underly friction. The third section focuses on dry, wearless friction in less complex systems. The discussion begins with simple one-dimensional models of friction between crystalline surfaces. These models illustrate general results for the origin and trends of static and kinetic friction, such as the importance of metastability and the effect of commensurability. Then two-dimensional studies are described, with an emphasis ...

show abstract

“…Theoretical work and computer simulations of Lennard-Jones fluids and hard spheres show that the oscillatory solvation force originates from the stratification or ordering of the molecules in layers when the fluid is confined by the surfaces [5][6][7][8][9][10][11][12][13][14][15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

Structure and solvation forces in confined films of alkanes

Dijkstra¹

1998

Thin Solid Films

View full text Add to dashboard Cite

We compute by computer simulations the solvation force of a system of linear and branched alkanes confined in a slab geometry. The solvation force for linear decane oscillates with distance with a periodicity close to the width of the molecules. The branched alkanes, 2-methylundecane and 2-methylheptane, show a similar oscillatory behaviour, however the oscillations are decreased with a factor of about three and show a long-range attractive force. In addition, we show that the critical temperature of the liquid-vapour coexistence of npentane shifts to lower temperatures upon confining.

show abstract

Solvation forces in simple dense fluids. I

Cited by 296 publications

References 23 publications

Advances in nonequilibrium molecular dynamics simulations of lubricants and additives

Advances in nonequilibrium molecular dynamics simulations of lubricants and additives

Computer Simulations of Friction, Lubrication, and Wear

Structure and solvation forces in confined films of alkanes

Contact Info

Product

Resources

About