Effect of polymer, poly(ethylene glycol)(PEG-400), on solvent and rotational relaxation of coumarin-480 in an ionic liquid containing microemulsions

The effect of a polymer, polyethylene glycol with a molecular weight of 400 (PEG-400), on the dynamics of solvent and rotational relaxation have been investigated in [bmim][BF4]/TX100/cyclohexane microemulsions using steady state and time resolved fluorescence spectroscopy as a tool and coumarin 480 (C-480) as a fluorescence probe. The size of the microemulsions increases with addition of PEG-400, which was revealed by dynamic light scattering (DLS) measurement. This leads to faster collective motion of the cations and anions of [bmim][BF4], which contributes to faster solvent relaxation in microemulsions.