The effect of urea on sodium bis(2-ethylhexyl) sulfosuccinate (AOT) reversed micelles films deposited on hydrophobic and hydrophilic glass substrates was studied by optical and electron microscopy. Films growth in the absence of urea presented a droplet aspect, whereas in its presence, the films had a more tubular structure and seemed to merge one into the other suggesting a less rigid micellar interface in the presence of urea. The observed differences in the mesophases were also reflected in the behavior of a nanoscale event, the dissociation of a photoacid added to the reversed micelles aqueous pools. Whereas in the absence of urea, no prototropic dissociation was observed, in its presence the emission of the conjugated base of the photoacid was detected indicating a more "watered" media for the occurrence of excited state prototropic reaction. This study shows a way to control structurally and chemically film from deposition of reversed micelles. (C) 2004 Elsevier B.V. All rights reserved.