Fluorescence anisotropy of ionic probes in AOT reverse micelles: influence of water droplet size and electrostatic interactions on probe dynamics

The effect of water droplet size and electrostatic interactions on the rotational diffusion of the probe molecules is studied. The reduction in the average reorientation time of fluorescein is shown to be a consequence of repulsive electrostatic interactions between the negatively charged probe and the anionic head groups of the surfactant di(2-ethylhexyl) sodium sulfosuccinate (AOT).