Temperature dependent solvation dynamics in an ionic liquid containing microemulsions of 1-butyl-3-methylimidazolium tetrafluoroborate/Triton X–100/cyclohexane

A study of the temperature-dependent solvation dynamics of coumarin-480 in [bmim][BF4]/Triton X-100/cyclohexane microemulsions at three different temperatures (299 K, 308 K and 317 K) is reported. The solvation dynamics of a room temperature ionic liquid in microemulsions becomes faster with increase in temperature. Dynamic light scattering measurements indicate a significant change in size with temperature for microemulsion systems with the hydrodynamic diameter decreasing with increase in temperature. Time-resolved fluorescence anisotropy studies reveal a decrease in the rotational restriction on the probe with increasing temperature. Wobbling-in-cone analysis of the anisotropy data also supports this finding.