Neutron scattering study of water confined in periodic mesoporous organosilicas

A series of quasi-elastic neutron scattering measurements were performed using IN6 at the Institute Laue Langevin for a mesoporous organosilica material with phenyl functions, called phenyltriethoxysilane (PTES). The aim of the experiment was to study the diffusion dynamics of nano-scale water clusters inside the hydrophobic pores as a function of temperature and hydration. By fitting the Debye–Waller factor, the data show clearly the different behavior between water, both inside and outside the hydrophobic pores, which resembles bulk water. The mean thermal displacement 〈u2〉 of the external water increases with T almost linearly up to 353 K, while the internal water quickly reaches the maximum at T∼323 K, indicating the confinement by an averaged pore diameter of the porous organosilica.

Graphical abstractThis paper concerns measurement of water dynamics associated within hydrophobic mesoporous organosilica material with phenyl functions as investigated using the quasielastic neutron scattering technique. By fitting the quasielastic neutron scattering results with Debye Waller factor, it show clearly the different behavior between water h inside and outside the hydrophobic pores.Figure optionsDownload full-size imageDownload as PowerPoint slide