DYNAMICAL BEHAVIOR OF THE GELATION PROCES S IN HYBRID MATERIALS

The gelation process in a nanocomposite material is studied using vari ous techniques. Then, the dynamical behavior is analysed, allowing the description of molecular and macromolecular motions in those complex systems. Photon Correlation Spectroscopy probes the formation of the g el network. Forced Rayleigh Scattering gives some information on the m icrostructure of the mixtures. NMR allows to discriminate the influenc e of the solid-like and liquid-like phases of the materials. Only slig ht changes are observed around the sol to gel conversion, whereas dras tic changes of the properties could be observed during more than ten t imes the characteristic t(g).