(452f) Using Monte Carlo Simulations to Study Wetting Behavior of Ionic Liquids

Room temperature ionic liquids (RTILs) are finding applications in many emerging technologies due to their low vapor pressures, high conductivities and excellent solvent capabilities. Understanding the wetting behavior of ionic liquids is crucial for developing these technologies. This presentation focuses on our efforts to use Monte Carlo simulations to study the effects of chemical nature of ionic liquids on their wetting properties. To understand the role of dispersion and coulombic interactions we study simple models of ionic liquids comprising of spherical cations and anions with variable strengths of electrostatic interactions relative to dispersion interactions. The range of relative ionic strengths that we investigate includes those observed in RTILs and molten alkali halides. Results are presented to show the dependence of contact angle on temperature and substrate strength for fluids with different relative ionic strengths. We also present results for realistic models of imidazolium based RTILs on graphite surface to show the effect of temperature and chemical nature of cation on the wetting properties. We briefly explain the challenges encountered in Monte Carlo simulations of realistic models of RTILs and the strategies we use to overcome them.