Confinement influence in liquid water studied by Raman and neutron scattering

We present a detailed Raman scattering study performed in liquid water conf ined in a porous sol-gel glass having 25 Angstrom diameter pores. The measu rements were carried out in the OH vibrational stretching region, ranging f rom 2700 cm(-1) to 3700 cm(-1). By comparing the bulk water with the confin ed one, strong modification of the vibrational dynamics of adsorbed water o n the inner surface of the glass matrix becomes clear. Furthermore a preliminary analysis of incoherent quasi-elastic neutron scat tering data (IQENS) in confined water reveals a strong confinement effect o n the water molecules by the host glass that reflects, consequentially, a h indered diffusional dynamics. The experimental results were interpreted fol lowing the well known Volino-Dianoux model.