J. Phys. IV France 10 (2000) Pr7-95-Pr7-98
A neutron scattering investigation of the structural properties of glassforming m-toluidine confined in MCM-41D. Morineau1, F. Casas1, C. Alba-Simionesco1, A. Grosman2, M.-C. Bellissent-Funel3 and N. Ratovélomanana4
1 Laboratoire de Chimie Physique, UMR 8611, bâtiment 490, Université Paris-Sud, 91405 Orsay cedex, France
2 Groupe de Physique des Solides, Tour 23, 2 place Jussieu, 75251 Paris cedex 05, France
3 Laboratoire Léon Brillouin, CE-Saclay, 91191 Gif-sur-Yvette, France
4 Laboratoire de Dynamique, Interactions et Réactivité, UPR 1580, 2 rue Henry Dunant, 94320 Thiais, France
The existence of a characteristic dynamical length of a few molecular diameters in deeply supercooled liquids have been recently supported by different experiments. The large implications of additional experimental evidences account for the growing interest in the study of size effects on the properties of confined supercooled liquids and phase transitions phenomena. Microscopic investigations on highly regular porous materials are chosen for a structural analysis of the "fragile" liquid m-toluidine confined in MCM-41. Neutron scattering experiments have been performed with MCM-41 of different porous diameters. For pore diameters smaller than 3 nm, the static structure factor of the confined liquid significantly differs from the bulk. Same results are observed for temperatures ranging from above the melting point to below the glass transition. The occurrence of a confinement effect for this system is likely not to be associated to the inhomogeneities of supercooled liquids.
© EDP Sciences 2000