Micellization Behavior of Novel Amino Acid–Based Surface-Active Ionic Liquids: Experimental Characterization and Enhanced Solubilization of Cyhalothrin

Three surface-active ionic liquids of trisubstituted amino acids (AASAILs) 1-dodecyl-2,3-dimethylimidazolium glycine [DMDIM][Gly], 1-dodecyl-2,3-dimethylimidazolium alanine [DMDIM][Ala], and 1-dodecyl-2,3-dimethylimidazolium phenylalanine [DMDIM][Phe] were designed and synthesized in the lab. The critical micelle concentration (CMC) was measured by the volume method and conductivity method to evaluate the surface activity of AASAILs, and thermodynamic properties including the molar Gibbs free energy ΔG0m, the enthalpy change ΔH0m, and the entropy change ΔS0m of micellization were also investigated. Moreover, the size distribution of the micellar structure was observed by dynamic light scattering (DLS). Importantly, the solubility of cyhalothrin was determined by UV–visible spectroscopy, and at the same time, comparisons with that in pure water were discussed. Besides that, the effects of the size of counterion on the surface activity and solubilization of cyhalothrin were also explored. Finally, it is found that [DMDIM][Phe] has not only the strongest solubilization capacity to cyhalothrin but also a good wettability on the Bougainvillea spectabilis leaves.