Confinement influence in liquid water studied by Raman and neutron scattering

We present a detailed Raman scattering study performed in liquid water confined in a porous sol-gel glass having 25 A diameter pores. The measurements were carried out in the OH vibrational stretching region, ranging from 2700 cm-1 to 3700 cm-1 . By comparing the bulk water with the confined one, strong modification of the vibrational dynamics of adsorbed water on the inner surface of the glass matrix becomes clear. Furthermore a preliminary analysis of incoherent quasi-elastic neutron scattering data (IQENS) in confined water reveals a strong confinement effect on the water molecules by the host glass that reflects, consequentially, a hindered diffusional dynamics. The experimental results were interpreted following the well known Volino-Dianoux model.