Neutron diffraction study of the structure of water confined in a sol-gel silica glass

During recent years, the understanding of the modification of the structural and dynamics of water confined in different environments has been the focus of much interest in scientific research. This topic is in fact of great relevance in a lot of technological areas and, in living systems, essential water related phenomena occur in restricted geometries in cells, and active sites of proteins and membranes, or at their surface. In this paper we report on neutron diffraction results on the microscopic structure of heavy water confined in a fully hydrated sol-gel silica glass (GelSil) as a function of the temperature, in comparison with that of bulk water. Furthermore, at low T, the nucleation of cubic ice superimposed to liquid water, already observed for water within Vycor glasses, is discussed