A Novel Zwitterionic Imidazolium-Based Ionic Liquid Surfactant: 1-Carboxymethyl-3-Dodecylimidazolium Inner Salt

A novel zwitterionic imidazolium-based ionic liquid (IL) surfactant, 1-carboxymethyl-3-dodecylimidazolium inner salt, was synthesized. The molecule structure was confirmed by means of electrospray ionization mass spectrometry, ¹H nuclear magnetic resonance and elemental analysis. The isoelectric point (pI) is 3.8 ± 0.1 at 35 ± 0.1 °C. The other important physicochemical parameters such as the critical micelle concentration (CMC), the surface tension at CMC (γ_CMC), the adsorption efficiency (pC ₂₀), the surface pressure at CMC (Π_CMC), the maximum surface excess (Γ_m), the minimum molecular cross-sectional area (A _min), the value of CMC/C ₂₀ and the average number of aggregation (N _m) were determined by surface tension and steady-state fluorescence probe methods, respectively.