Application of curcumin in mixed properties of quaternary N-alkyl tropine-based ionic liquid surfactant with nonionic, anionic and zwitterionic surfactants

Curcumin has been found to be sensitive to the solution environment and has aroused great interest. Based on this, UV spectrophotometry with curcumin as a probe was employed to investigate the solution properties of surfactants. The reliability of UV spectrophotometry using curcumin as a probe was confirmed by comparing the outcomes with those obtained by surface tension method. The micellization behaviors of surfactant mixtures of tropine-based ionic liquid surfactant (TILS) with anionic surfactant sodium dodecyl sulfate (SDS), nonionic surfactant Triton X-100 (TX-100), and zwitterionic surfactant N-dodecyl-N,N-dimethylglycine (BS-12) were investigated, respectively. Based on the theory of regular solutions, the interaction parameters between the two surfactants and their corresponding thermodynamic parameters were analyzed. The negative β m and | β m | > |ln( CMC 1 / CMC 2 )| suggest intense attraction between two different surfactants. Thermodynamic parameters indicate that micelle formation is an exothermic and entropy-increasing process. Comparing the interaction parameters of the three systems, it is evident that TILS exhibits stronger synergistic effects in the formation of mixed micelles with SDS as compared to TX-100 and BS-12. These results demonstrate the feasibility of using curcumin for the study of surfactant compounding properties and broaden the application range of curcumin.