Investigating Processes Occurring in Acoustically Levitated Ionic Liquid Droplets

Abstract

Chemical processes that occur in small volume containers have many benefits that have only recently become apparent. Acoustic levitation is one technique for the suspension of small volumes, most commonly droplets, in a “contact-free” container that preserves the droplet’s large surface area. In our laboratory we are coupling acoustic levitation and droplet chemistry with room temperature ionic liquids (RTILs), which are rapidly becoming the solvent of choice for many systems due primarily their unique “tunability” and low vapor pressures. In this work we measure the temperature of acoustically-levitated droplets of deionized water, the low vapor pressure solvent toluene and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (BMP-BTI) ionic liquid. Preliminary results suggest that the BMP-BTI ionic liquid may be a more suitable media for solvating acoustically-levitated droplets as compared to water and toluene due the negligible evaporative cooling effect seen in BMP-BTI droplets, leading to droplet long persistence lifetimes and increased thermal stability.