Article révisé par les pairs
Résumé : Analysis of the fluorescence decay of a probe dissolved in the water core of reverse micelles has been reported as a means to measure the internal microviscosity of water under the assumption of a homogeneous distribution of the probe. We have carried out a computer analysis which shows that divergence from homogeneity associated with solvation enthalpy changes ΔGo as small as 0.5 kJ mole-1 is sufficient to affect significantly the fluorescence response of the system. There are known examples of non-homogeneous distribution of a solute within the water pool of a reverse micelle and we are led to conclude that if a homogeneous distribution of the excited probe is to be assumed, then the decay of its fluorescence is an unreliable technique for studying the microscopic internal properties of reverse micelles. © 1988.