Dynamics of solvation and rotational relaxation in neutral Brij 35 and Brij 58 micelles

Solvation dynamics of Coumarin 480 (C-480) and Coumarin 490 (C-490) in neutral polyoxyethylene (23) lauryl ether (Brij 35) and polyoxyethylene (20) cetyl ether (Brij 58) micelles is severely retarded compared to pure water. The solvation dynamics is biexponential in all these micelles. The fast component of the solvation dynamics arises due to the water molecules present in the palisade layer of the micelles. The slow nanosecond component in solvation dynamics may arise due to the hydrogen bonding of water molecules with the polar part of micelles. The rotational relaxations in all these micelles are bimodal and comprising of a picosecond and a nanosecond component.