A neutron scattering investigation of the structural properties of glassforming m-toluidine confined in MCM-41

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