Background: Molecular dynamics simulation was performed to study the thermodynamic, structural and dynamic properties of the ionic liquid mixture of 1-ethyl-3-methylimidazolium methylsulfate and water in different molar fractions at a pressure of 101.3 kPa and a temperature of 300 K.
Aim: The purpose of this study is to investigate properties such as the orientation of anion and cation relative to each other and relative to water, distribution of water clusters, hydrogen bonds and their dynamics, diffusion coefficient and ion pair dynamics with with change in molar fraction in the ionic liquid and water mixtures. Also, the relationship between microscopic properties and macroscopic properties is investigated.
Methodology: In this thesis, the simulation steps were carried out from the beginning until reaching equilibrium and calculating the structural and transport properties of the mixture of ionic liquid and water with different molar fractions. The initial stages include choosing the configuration, initial speeds and calculating the force parameters. Equilibration of the system is controlled by properties such as pressure, temperature and energy. After the system reached equilibrium, different parameters were calculated and then compared.
Conclusions: The results obtained for the density, distribution of water clusters, hydrogen bonding and diffusion coefficient in this research are in good agreement with the experimental results and previous studies that due to the asymmetry and the large size of the ions, there are a large number of holes in ionic liquids in concentrated solutions these cavities are filled by water molecules or small water clusters. The results of this study showed that with the increase of the water molar fraction in mixtures with a water molar fraction less than 0.3, initially some increase in density and then a slight decrease in density is observed. Comparing the radial distribution function and coordination number of water-cation with water