17th April 2007 – 15:00
Prof. Mauro Rovere (Università degli Studi di Roma Tre)
Water plays an important role in many natural processes where it is confined or at contact with substrates. Examples can be found in different fields of geology, biology, chemical engineering. Changes in the static and dynamical properties of water are expected to take place for the geometrical constraints and the interaction with the different substrates. In particular it has been shown that confined water can be more easily supercooled in experiments.
The presentation summarizes Molecular Dynamics results obtained for water confined in a silica pore and presents recent results on water embedded in a hydrophobic matrix. For water confined in a silica pore it is found that the interaction with the hydrophilic surface and the geometrical constraints give rise to layering effects of great relevance in modifying static and dynamical properties with respect to the bulk phase. For water at contact with an hydrophobic matrix a study of the thermodynamical behaviour upon supercooling shows modifications in the limit of stability of water. The hydrophobic effect however does not change the general trends of the liquid spinodal.