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Several model oil-water-surfactant multiphase microemulsion systems have been studied. Dispersion sizes in the microemulsion phase with X-ray scattering, interfacial tensions between the different phases with surface light scattering and surfactant film bending elasticity with ellipsometry were measured. A comparison between the data and the existing theories was made. Microemulsion phases structural studies have emphasized the importance of the properties of the surfactant film through the parameters of spontaneous curvature and of the film curvature elastic modulus. The measurement of film bending elasticity allowed the calculation of the persistence length of the film which is in qualitative agreement with the one required to explain the bulk structure observed at optimal salinity. The detailed calculations of the interfacial tensions from available theories do not agree well with the experimental measurements. However, an approximate and simple relation has been found to calculate the optimal interfacial tensions. Molecular diffusion in a model porous medium with a fluorescence recovery technique was also studied. Scale dependent diffusion with two asymptotic regimes were evidenced; free diffusion for scales much smaller than the mean pore size and averaged diffusion at large scales. A simple model was used to interpret the data, which led to a detailed description of the structure of the porous media.

Additional information

Authors: LANGEVIN D, Laboratoire de Spectroscopie Hertzieneen de l'Ecole Normale Supérieure, 45, rue d'Ulm, F-75230 Paris Cedex 05 (FR)
Bibliographic Reference: EUR 12286 EN (1989) FS, 18 pp., ECU 5
Availability: (2)
ISBN: ISBN 92-826-0814-X; CD-NA
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