Catherine FUNG1, Susan PERKIN1
1University of Oxford, Oxford, United Kingdom
The vast possibilities presented by ionic liquids enables them to have diverse applications in areas such as solvent extraction, energy storage, and carbon dioxide capture. Despite the increasing interest in their applications, their properties, in particular, their electrical properties near charged interfaces, are not well understood. An anomalous long-range interaction which deviates from the predictions of the Debye-Hückel theory, has been observed in concentrated electrolytes (termed underscreening), including in ionic liquids. In order to probe the character of these long-range interactions, we present surface forces measurements across thin films of a protic ionic liquid, ethylammonium nitrate, at different concentrations in water between mica surfaces. These results are important for understanding the physics of concentrated electrolytes and aid the interpretation of the anomalous underscreening.