Femtosecond study of solvation dynamics of DCM in micelles

Solvation dynamics of 4-(dicyanomethylene)-2-methyl-6-(p-dimethylamino-styryl) 4H-pyran (DCM) has been studied in neutral (triton X-100, TX) and cationic (cetyl trimethyl ammonium bromide, CTAB) micelles using femtosecond upconversion. Since DCM is insoluble in bulk water the observed solvation dynamics reports the relaxation dynamics exclusively at the micellar interface. It is observed that the solvation dynamics in TX is slower than that in CTAB. The solvation dynamics is described by components of 2.1, 165 and 2050 ps for TX and 0.23, 6.5 (average 1.75 ps) and 350 ps for CTAB.