J. Phys. IV France 10 (2000) Pr7-211-Pr7-214
Diffusional and vibrational properties of water confined in very thin nanoporous glasses probed by light and neutron scatteringV. Venuti1, V. Crupi1, S. Magazù1, D. Majolino1, P. Migliardo1 and M.C. Bellissent-Funel2
1 Dipartimento di Fisica dell'Università & INFM di Messina, C.da Papardo, S.ta Sperone 31, P.O. Box 55, 98166 S. Agata, Messina, Italy
2 Laboratoire Léon Brillouin, CEA-CNRS, CEA-Saclay, 91197 Gif-sur-Yvette cedex, France
Rayleigh-wing, Raman and quasi-elastic neutron scattering data on water confined into nanoporous glasses (silica 26 Å pores), are presented and discussed. The H-bond among water molecules and Si-OH surface groups originates strong hydration effects, that induce more stable structural environments in which the memory of collective modes (the [Math]60 cm-1 and [Math]190 cm-1 shoulders due to the HB bending and HB stretching modes of water) is lost and the O-H stretching band connected to low-density water tends to disappear. The quasi-elastic neutron response is explained in terms of two available current models : the Dianoux-Volino model and the MCT model.
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