Aqueous Ionic Liquid Mixtures as Minimal Models of Lipid Bilayer Membranes.

We introduce aqueous ionic liquid (IL) mixtures, specifically mixtures of 1-butyl-3-imidazoliumtetrafluoroborate (BMImBF), with water as a minimal model of lipid bilayer membranes. Imidazolium-based ILs are known to form clustered nanoscale structures in which local inhomogeneities, micellar or lamellar structures, are formed to shield hydrophobic parts of the cation from the polar cosolvent (water). To investigate these nanostructures, dynamic light scattering (DLS) on samples with different mixing ratios of water and BMImBF was performed.

Nanoscopic structures and molecular interactions leading to a dystectic and two eutectic points in [EMIm][Cl]/urea mixtures.

Deep eutectic solvents (DES) are a novel class of ionic liquid-based solvents, combining an organic salt and a hydrogen bond acceptor (HBA) at specific molar ratios. The resulting DES mixtures often have strongly depressed freezing points and feature properties well-known for ionic liquids as non-classical solvents. In this study, mixtures of 1-ethyl-3-methylimidazolium chloride ([EMIm][Cl]) and urea are investigated at different molar ratios mainly via electron paramagnetic resonance (EPR) spectroscopy on chemical environment-specific nitroxide-based spin probes, aided by differential scanning calorimetry (DSC) to obtain insights into the structure, dynamics, and molecular processes on the nanoscale.