Ionic liquids have favorable intrinsic properties that make them of interest as solvents for various chemical reactions. The same properties that make the liquids effective solvents also make them interesting liquids for studies involving sonochemistry, acoustic cavitation, and sonoluminescence. Recent interest in using ultrasound to accelerate chemical reactions conducted in ionic liquids necessitates an understanding of the effects of acoustic cavitation on these solvents. Here, we review our previous results on the effects of cavitation on some room-temperature ionic liquids, including the sonoluminescence spectra of molten salt eutectics and concentrated aqueous electrolyte solutions. In all cases, regardless of the essentially nonexistent vapor pressure of the solution atomic and small molecule emitters are observed in the spectra which arise from sonolysis of the ionic liquids.
Bibliographical noteFunding Information:
We thank Drs. Y. Didenko, J.D. Oxley, T. Prozorov and A. Lawrence for helpful discussions and the preparation of some ionic liquids. This work was funded by the NSF (CHE-0315494). Portions of this research were carried out in the Center for Microanalysis of Materials, University of Illinois at Urbana-Champaign, which is partially supported by the US Department of Energy under Grant DEFG02-91-ER45439.
- Acoustic cavitation
- Ionic liquids
- Molten salts