Molecular Dynamics Simulation and Its Application to Nano-rheology

Over the last 15 years molecular dynamics (MD) simulations have become one of the important tools to tackle many of the complex problems that are faced by rheologists and engineers. The advent of modern areas of science such as nanotechnology and the need to understand physical phenomena including rheology and tribology at the molecular scale have helped the growth of research both experimentally and computationally at nano-scales. Molecular dynamics simulations among other molecular simulation methods have been used for computational research in those areas. Application of molecular dynamics to rheology has helped to understand the behaviour of polymers qualitatively; also important progress has been made in predicting quantitative rheological properties such as the viscosity of simpler liquids (such as alkanes). In particular the application of MD to the behaviour of confined fluids and lubricants at nano-scales has revealed some important properties and explained the underlying physics of observed phenomena that include enhanced viscosity and relaxation times and the role of normal stress differences in supporting large loads. MD has been a valuable tool in studying the relationship of the molecular structure and the rheological properties. In this review we will give an introduction about the method and will discuss some of the progress made to date. Our main focus will be on the application of MD in the nano-rheology of ultra-thin confined films.