Comparative structural study of aqueous fluorinated non-ionic micelles

The water phase behaviour of non-ionic fluorinated surfactant-based systems depends upon the chemical structure of the surfactant polar head. The two examined systems present a lower consolute curve with different critical temperatures and concentrations. The intrinsic viscosity measurements in the dilute regime show that the micelles, obtained with the surfactant having a bulky polar head (two hydrophilic chains) are spherical, whereas the micelles obtained with the surfactant having only one hydrophilic chain are more elongated. These results are confirmed by a more detailed structural study by small-angle neutron scattering of the micellar solutions. This work shows a correlation between the micelle shape and the critical concentration value (C) 1998 Elsevier Science B.V.