Microstructures, interactions and dynamics properties studies of aqueous guanidinium triflate ionic liquid from molecular dynamics simulations

Abstract

In order to understand the phase equilibrium behavior of aqueous ionic liquids (ILs) guanidinium triflate [gua][OTf] solution (binary solvent) at 7 different molar fractions of water ranged from 0.1 to 0.7 at 440.15K classical molecular dynamic simulations were performed. The simulations measured changes in different properties such as density, structural, bonding properties (radial distribution function, water clustering and hydrogen bonding) and dynamic property (diffusion coefficient). The analysis of radial distribution and spatial distribution functions revealed a significant long-range structural correlation between IL and water. Water molecules intercalated in the coordination shell of both ions, thus weakening their electrostatic interaction. It was observed that, water molecules started to connect with each other and formed a large hydrogen bond network throughout the system with the increasing water molar fraction. Thus, improved both translational and rotational motions of [gua]+ and [OTf]− ions significantly. As the results, [OTf]− ions diffused faster than [gua]+ ions and improved both translational and rotation motions of the ions mentioned significantly. The application of aqueous [gua][OTf] at high temperature has a promising potential particularly in the carbon dioxide removal area for natural gas industry.