Dielectric behavior of Water in [bmim] [Tf 2 N] room-temperature Ionic Liquid, molecular dynamic study

TL;DR

This study uses molecular dynamics simulations to analyze how water's dielectric properties change when mixed with the ionic liquid [bmim][Tf2N], introducing a novel flexible water model for improved accuracy.

Contribution

The paper presents a new flexible 3-site water model and investigates dielectric and thermodynamic properties of water-ionic liquid mixtures through molecular dynamics simulations.

Findings

Observed phase separation at certain concentrations.

Dielectric properties are significantly affected by ionic liquid presence.

New flexible water model improves simulation accuracy.

Abstract

In this work we present the dielectric behavior of water with a novel flexible model that improved all three sites water models Different concentrations of the ionic liquid 1- butyl-3-methylimidazolium [bmim] bis(trifluoromethanesulfonyl)imide [Tf 2 N] with water was investigated. The study was performed by molecular dynamics simulations using three water models, being two non-polarizable 3-site SPC/E and SPC/e, and a novel flexible 3-site FAB/epsilon model. Systematic thermodynamics, dynamical and dielectric properties were investigated, such as density, diffusion coefficient, heat of vaporization Delta-Hvap, and surface tension at 300 K and 1 bar. We extrapolated the experimental molar fraction of the mixtures and a pattern change for all properties was observed, evidencing the phase separation previously reported by experimental data. The results also display the dielectric effect of the system on the calculated properties.