Simple: Just add salt
Developing even more ionic ionic liquids
In the most recent edition of Chemical Communications, researchers from the Molecular Thermodynamics Lab and collaborators explore the possibility of making ionic liquids even more ionic by adding common inorganic salts to these liquid organic salts of multiple applications.
Ionic liquids are distinct from other chemical substances because they may be designed and engineered in such a fashion that all chemical tools already known to exist in all other chemicals may be present. Making them more organic-like has been a major task. However, providing ionic liquids with an even greater ionic (salt-like) character, without losing their liquid status, has not been exploited.
Ionic liquids are incredible solvents. They are composed of two charged units (anion and cation) and the nature of these ions determines their interactions with other molecules thereby governing their solvent power. In the ionic liquid world, the trend has been to decrease the degree of their ionic character (ionicity) but researchers have now demonstrated that simply adding common inorganic salts (containing sodium, calcium or ammonium) is an excellent cheap alternative to move in the opposite direction. The resulting mixtures, labeled HILLs - for High Ionicity Ionic Liquids – are solely made up of ions, and are liquid at a wide range of temperatures and concentrations. This new strategy offers extra flexibility to the use of these extraordinary compounds in all known applications, in particular in those which require higher electrical conductivity (e.g. batteries and fuel cells).
Chemical Communications, a journal of the the Royal Society of Chemistry, publishes urgent, high quality communications from across the chemical sciences.
Inorganic Salts in Purely Ionic Liquid Media: The Development of High Ionicity Ionic Liquids (HIILs)
Ana B. Pereiro, João Miguel Mendes de Araújo, Filipe S. Oliveira, Carlos E. S. Bernardes, José M.S.S. Esperança, Jose Nuno Canongia Lopes, Isabel M Marrucho and Luis Paulo N. Rebelo