Aggregation Behavior of Triton X-100 with a Mixture of Two Room-Temperature Ionic Liquids: Can We Identify the Mutual Penetration of Ionic Liquids in Ionic Liquid Containing Micellar Aggregates?

In this manuscript,. we have characterized two different micellar aggregates containing all nonvolatile components;. We have shown the effect of ethylammonium nitrate (EAN) addition on the properties of micellar solution of Triton X-100 in 1-butyl-3-methylimidazolium hexafluorophosphate (bmimPF(6)) and (ii) the effect. of bmimPF(6) addition on the properties of micellar solution Of Triton X-100 in EAN. To investigate the effect, we have used H-1 NMR, pulsed field gradient spin-echo NMR (PFGSE NMR), and Methyl orange (MO) and coumarin 153 (C-153) as absorption and emission probes, respectively The penetration of added EAN inside the Triton X-100/bmimPF(6) micellar aggregates is indicated by (i) red shift. in both the absorption spectra of MO and emission spectra Of C-153 and (ii) downfield shift of proton signals of ethylene oxide units in Triton X-100. On the other hand, H-1 NMR and PFGSE NMR indicates the penetration of added bmimPF(6) inside the Triton X-100/EAN micellar aggregates. However, the constancy of both the,absorption spectra. Of MO and emission spectra of C-153 indicates that the microenvironment around the probe molecules remains unaffected. We have also investigated: the effect of micelle formation and the effect of penetration of ionic liquids (ILs) in micellar aggregates, on the solvation dynamics of C-153: The solvent relaxation around C-153 gets retarded on going from neat ILs to the Micellar solution of Triton X 100 in ILs In addition to this, we have also observed that with the addition Of EAN in Triton X-100/bmimpF(6) micellar aggregates the solvation dynamics becomes faster; whereas with the addition of bmimPF(6) in Triton X-100/EAN micellar aggregates we did not observe any notable change in salvation dynamics. This observation further supports the conclusions drawn from UV-visible and NMR studies.