Solvation dynamics in a worm-like CTAB micelle

The solvation dynamics of 4-(dicyanomethylene)-2-methyl-(p-dimethyl-aminostyryl) 4Hpyran (DCM) is studied in a worm-like micelle consisting of cetyl trimethylammonium bromide (CTAB) and sodium salicylate (NaSal). Solvation dynamics in the worm-like micelle is found to be about 4-times slower than that in ordinary CTAB micelle. This indicates that the fluorescent probe molecule (DCM) experience a different microenvironment inside the worm-like micellar aggregates compared to that in ordinary spherical CTAB micelle. The spectral width (Γ) of the time resolved emission spectra of DCM in the micellar aggregates is found to be time dependent. This is ascribed to the diffusion of the probe (DCM).