Self‐Assembled Gels formed in Deep Eutectic Solvents : Supramolecular Eutectogels with High Ionic Conductivities

This paper reports the ability of 1,3:2,4‐dibenzylidene‐D‐ sorbitol (DBS), a simple, commercially‐relevant compound, to self‐assemble as a result of intermolecular non‐covalent interactions into supramolecular gels in deep eutectic solvents (DESs). The DESs are based on choline chloride combined with alcohols/ureas – DBS forms gels at a loading of 5% wt/vol. Rheology confirms the gel‐like nature of the materials, electron microscopy indicates underpinning nanofibrillar DBS networks and differential scanning calorimetry shows the deep eutectic solvent nature of the liquid‐like phase is retained. The ionic conductivities of the gels are similar to those of the unmodified DESs proving the deep eutectic nature of the ionic liquid‐like phase. Gelation is tolerant of ionic additives Li+, Mg2+ and Ca2+, with the resulting gels having similar conductivities to electrolyte dissolved in the native DES. The low‐molecular‐weight gelator DBS is a low‐cost additive – forming gels in DESs from readily‐available constituents, with conductivity levels suitable for practical applications. We suggest supramolecular eutectogels have potential uses ranging from energy technology to synthesis and catalysis.