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 diame ters in deeply supercooled liquids have been recently supported by differen t experiments. The large implications of additional experimental evidences account for the growing interest in the study of size effects on the proper ties of confined supercooled liquids and phase transitions phenomena. Micro scopic investigations on highly regular porous materials are chosen for a s tructural 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 structu re 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 t his system is likely not to be associated to the inhomogeneities of superco oled liquids.