Parametric Study of Lennard–Jones Potentials to Predict Physical Behavior via Coarse-Grained Molecular Dynamics Simulations of Water and Ethylene Glycol Over Wide Temporal and Spatial Scales

Abstract

To develop advanced and elaborate nanotechnologies, the behavior of materials must be understood at the nanoscale. Since direct observation is not generally possible experimentally, molecular dynamics simulations have been used to estimate nanoscale behavior, although simulations still have spatio-temporal limitations. Thus, coarse-grained molecular dynamics (CGMD) simulations have been suggested to study the physical properties and molecular behavior of mesoscale systems. A 'bead' composed of several atoms or molecules can represent the physical properties of a materials. In this study, we performed CGMD simulations of water and ethylene glycol, represented by Lennard-Jones parameters with various numbers of molecules within a single bead, to determine interaction parameters by comparing our results against empirically determined physical properties. Our results show the possible range of the number of molecules per bead satisfying a particular physical property such as density and self-diffusion coefficient. These data yielded the most suitable number of molecules to be included in a bead for CGMD simulations containing water and ethylene glycol. Moreover, we identified and discussed the effects of time scale factor, of which the empirically applicable range of 4-10, on self-diffusivity coefficients.