Novel water-in-hydrophobic ionic liquid microemulsions with electropositive interface stabilized by monotonic cationic surfactant

The preparation of a novel microemulsion system stabilized by a monotonic cationic surfactant in a hydrophobic ionic liquid is presented in this study. The microemulsion is formed in the presence of a cosurfactant, n-hexanol, which facilitates the cationic surfactant to self-assemble into reverse micelles. By employing cosurfactant titration, the composition of both the continuous hydrophobic ionic liquid phase and the interfacial film was determined. A thorough investigation of the pseudoternary phase diagram, including the influence of varying cationic surfactants and n-hexanol amounts, was discussed. The formation of a water-in-hydrophobic ionic liquid microemulsion at 35 °C was confirmed through UV-Vis, FT-IR, and 1H-NMR techniques. Additionally, dynamic light scattering measurements revealed the aggregation size and spherical shape of CPB aggregations formed in hydrophobic ionic liquids.